Merge bef4e20434334d450a9d3cf3a41ada9c6cde1535 into 1dc4c248d1022dc9f3b6e3e899857404f6c680a1

Co-authored-by: Laurenz <laurmaedje@gmail.com>

.github/workflows/ci.yml

@@ -103,3 +103,15 @@ jobs:
       - uses: Swatinem/rust-cache@v2
       - run: cargo install --locked cargo-fuzz@0.12.0
       - run: cd tests/fuzz && cargo fuzz build --dev
+
+  miri:
+    name: Check unsafe code
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          components: miri
+          toolchain: nightly-2024-10-29
+      - uses: Swatinem/rust-cache@v2
+      - run: cargo miri test -p typst-library test_miri

Cargo.lock

@@ -2971,8 +2971,12 @@ dependencies = [
 name = "typst-html"
 version = "0.13.1"
 dependencies = [
+ "bumpalo",
  "comemo",
  "ecow",
+ "palette",
+ "time",
+ "typst-assets",
  "typst-library",
  "typst-macros",
  "typst-svg",

crates/typst-cli/src/world.rs

@@ -12,7 +12,7 @@ use typst::foundations::{Bytes, Datetime, Dict, IntoValue};
 use typst::syntax::{FileId, Lines, Source, VirtualPath};
 use typst::text::{Font, FontBook};
 use typst::utils::LazyHash;
-use typst::{Library, World};
+use typst::{Library, LibraryExt, World};
 use typst_kit::fonts::{FontSlot, Fonts};
 use typst_kit::package::PackageStorage;
 use typst_timing::timed;

crates/typst-eval/src/markup.rs

@@ -186,7 +186,7 @@ impl Eval for ast::Raw<'_> {
         let lines = self.lines().map(|line| (line.get().clone(), line.span())).collect();
         let mut elem = RawElem::new(RawContent::Lines(lines)).with_block(self.block());
         if let Some(lang) = self.lang() {
-            elem.push_lang(Some(lang.get().clone()));
+            elem.lang.set(Some(lang.get().clone()));
         }
         Ok(elem.pack())
     }
@@ -219,9 +219,8 @@ impl Eval for ast::Ref<'_> {
             .expect("unexpected empty reference");
         let mut elem = RefElem::new(target);
         if let Some(supplement) = self.supplement() {
-            elem.push_supplement(Smart::Custom(Some(Supplement::Content(
-                supplement.eval(vm)?,
-            ))));
+            elem.supplement
+                .set(Smart::Custom(Some(Supplement::Content(supplement.eval(vm)?))));
         }
         Ok(elem.pack())
     }
@@ -252,7 +251,7 @@ impl Eval for ast::EnumItem<'_> {
         let body = self.body().eval(vm)?;
         let mut elem = EnumItem::new(body);
         if let Some(number) = self.number() {
-            elem.push_number(Some(number));
+            elem.number.set(Some(number));
         }
         Ok(elem.pack())
     }

crates/typst-eval/src/math.rs

@@ -80,17 +80,17 @@ impl Eval for ast::MathAttach<'_> {
         let mut elem = AttachElem::new(base);
 
         if let Some(expr) = self.top() {
-            elem.push_t(Some(expr.eval_display(vm)?));
+            elem.t.set(Some(expr.eval_display(vm)?));
         }
 
         // Always attach primes in scripts style (not limits style),
         // i.e. at the top-right corner.
         if let Some(primes) = self.primes() {
-            elem.push_tr(Some(primes.eval(vm)?));
+            elem.tr.set(Some(primes.eval(vm)?));
         }
 
         if let Some(expr) = self.bottom() {
-            elem.push_b(Some(expr.eval_display(vm)?));
+            elem.b.set(Some(expr.eval_display(vm)?));
         }
 
         Ok(elem.pack())

crates/typst-eval/src/rules.rs

@@ -1,6 +1,6 @@
 use typst_library::diag::{warning, At, SourceResult};
 use typst_library::foundations::{
-    Element, Fields, Func, Recipe, Selector, ShowableSelector, Styles, Transformation,
+    Element, Func, Recipe, Selector, ShowableSelector, Styles, Transformation,
 };
 use typst_library::layout::BlockElem;
 use typst_library::model::ParElem;
@@ -62,8 +62,7 @@ fn check_show_par_set_block(vm: &mut Vm, recipe: &Recipe) {
         if let Some(Selector::Elem(elem, _)) = recipe.selector();
         if *elem == Element::of::<ParElem>();
         if let Transformation::Style(styles) = recipe.transform();
-        if styles.has::<BlockElem>(<BlockElem as Fields>::Enum::Above as _) ||
-           styles.has::<BlockElem>(<BlockElem as Fields>::Enum::Below as _);
+        if styles.has(BlockElem::above) || styles.has(BlockElem::below);
         then {
             vm.engine.sink.warn(warning!(
                 recipe.span(),

crates/typst-html/Cargo.toml

@@ -13,14 +13,18 @@ keywords = { workspace = true }
 readme = { workspace = true }
 
 [dependencies]
+typst-assets = { workspace = true }
 typst-library = { workspace = true }
 typst-macros = { workspace = true }
 typst-syntax = { workspace = true }
 typst-timing = { workspace = true }
 typst-utils = { workspace = true }
 typst-svg = { workspace = true }
+bumpalo = { workspace = true }
 comemo = { workspace = true }
 ecow = { workspace = true }
+palette = { workspace = true }
+time = { workspace = true }
 
 [lints]
 workspace = true

crates/typst-html/src/css.rs

@@ -0,0 +1,135 @@
+//! Conversion from Typst data types into CSS data types.
+
+use std::fmt::{self, Display};
+
+use typst_library::layout::Length;
+use typst_library::visualize::{Color, Hsl, LinearRgb, Oklab, Oklch, Rgb};
+use typst_utils::Numeric;
+
+pub fn length(length: Length) -> impl Display {
+    typst_utils::display(move |f| match (length.abs.is_zero(), length.em.is_zero()) {
+        (false, false) => {
+            write!(f, "calc({}pt + {}em)", length.abs.to_pt(), length.em.get())
+        }
+        (true, false) => write!(f, "{}em", length.em.get()),
+        (_, true) => write!(f, "{}pt", length.abs.to_pt()),
+    })
+}
+
+pub fn color(color: Color) -> impl Display {
+    typst_utils::display(move |f| match color {
+        Color::Rgb(_) | Color::Cmyk(_) | Color::Luma(_) => rgb(f, color.to_rgb()),
+        Color::Oklab(v) => oklab(f, v),
+        Color::Oklch(v) => oklch(f, v),
+        Color::LinearRgb(v) => linear_rgb(f, v),
+        Color::Hsl(_) | Color::Hsv(_) => hsl(f, color.to_hsl()),
+    })
+}
+
+fn oklab(f: &mut fmt::Formatter<'_>, v: Oklab) -> fmt::Result {
+    write!(f, "oklab({} {} {}{})", percent(v.l), number(v.a), number(v.b), alpha(v.alpha))
+}
+
+fn oklch(f: &mut fmt::Formatter<'_>, v: Oklch) -> fmt::Result {
+    write!(
+        f,
+        "oklch({} {} {}deg{})",
+        percent(v.l),
+        number(v.chroma),
+        number(v.hue.into_degrees()),
+        alpha(v.alpha)
+    )
+}
+
+fn rgb(f: &mut fmt::Formatter<'_>, v: Rgb) -> fmt::Result {
+    if let Some(v) = rgb_to_8_bit_lossless(v) {
+        let (r, g, b, a) = v.into_components();
+        write!(f, "#{r:02x}{g:02x}{b:02x}")?;
+        if a != u8::MAX {
+            write!(f, "{a:02x}")?;
+        }
+        Ok(())
+    } else {
+        write!(
+            f,
+            "rgb({} {} {}{})",
+            percent(v.red),
+            percent(v.green),
+            percent(v.blue),
+            alpha(v.alpha)
+        )
+    }
+}
+
+/// Converts an f32 RGBA color to its 8-bit representation if the result is
+/// [very close](is_very_close) to the original.
+fn rgb_to_8_bit_lossless(
+    v: Rgb,
+) -> Option<palette::rgb::Rgba<palette::encoding::Srgb, u8>> {
+    let l = v.into_format::<u8, u8>();
+    let h = l.into_format::<f32, f32>();
+    (is_very_close(v.red, h.red)
+        && is_very_close(v.blue, h.blue)
+        && is_very_close(v.green, h.green)
+        && is_very_close(v.alpha, h.alpha))
+    .then_some(l)
+}
+
+fn linear_rgb(f: &mut fmt::Formatter<'_>, v: LinearRgb) -> fmt::Result {
+    write!(
+        f,
+        "color(srgb-linear {} {} {}{})",
+        percent(v.red),
+        percent(v.green),
+        percent(v.blue),
+        alpha(v.alpha),
+    )
+}
+
+fn hsl(f: &mut fmt::Formatter<'_>, v: Hsl) -> fmt::Result {
+    write!(
+        f,
+        "hsl({}deg {} {}{})",
+        number(v.hue.into_degrees()),
+        percent(v.saturation),
+        percent(v.lightness),
+        alpha(v.alpha),
+    )
+}
+
+/// Displays an alpha component if it not 1.
+fn alpha(value: f32) -> impl Display {
+    typst_utils::display(move |f| {
+        if !is_very_close(value, 1.0) {
+            write!(f, " / {}", percent(value))?;
+        }
+        Ok(())
+    })
+}
+
+/// Displays a rounded percentage.
+///
+/// For a percentage, two significant digits after the comma gives us a
+/// precision of 1/10_000, which is more than 12 bits (see `is_very_close`).
+fn percent(ratio: f32) -> impl Display {
+    typst_utils::display(move |f| {
+        write!(f, "{}%", typst_utils::round_with_precision(ratio as f64 * 100.0, 2))
+    })
+}
+
+/// Rounds a number for display.
+///
+/// For a number between 0 and 1, four significant digits give us a
+/// precision of 1/10_000, which is more than 12 bits (see `is_very_close`).
+fn number(value: f32) -> impl Display {
+    typst_utils::round_with_precision(value as f64, 4)
+}
+
+/// Whether two component values are close enough that there is no
+/// difference when encoding them with 12-bit. 12 bit is the highest
+/// reasonable color bit depth found in the industry.
+fn is_very_close(a: f32, b: f32) -> bool {
+    const MAX_BIT_DEPTH: u32 = 12;
+    const EPS: f32 = 0.5 / 2_i32.pow(MAX_BIT_DEPTH) as f32;
+    (a - b).abs() < EPS
+}

crates/typst-html/src/lib.rs

@@ -1,13 +1,19 @@
 //! Typst's HTML exporter.
 
+mod css;
 mod encode;
+mod rules;
+mod typed;
 
 pub use self::encode::html;
+pub use self::rules::register;
 
 use comemo::{Track, Tracked, TrackedMut};
 use typst_library::diag::{bail, warning, At, SourceResult};
 use typst_library::engine::{Engine, Route, Sink, Traced};
-use typst_library::foundations::{Content, StyleChain, Target, TargetElem};
+use typst_library::foundations::{
+    Content, Module, Scope, StyleChain, Target, TargetElem,
+};
 use typst_library::html::{
     attr, tag, FrameElem, HtmlDocument, HtmlElem, HtmlElement, HtmlFrame, HtmlNode,
 };
@@ -18,9 +24,19 @@ use typst_library::layout::{Abs, Axes, BlockBody, BlockElem, BoxElem, Region, Si
 use typst_library::model::{DocumentInfo, ParElem};
 use typst_library::routines::{Arenas, FragmentKind, Pair, RealizationKind, Routines};
 use typst_library::text::{LinebreakElem, SmartQuoteElem, SpaceElem, TextElem};
-use typst_library::World;
+use typst_library::{Category, World};
 use typst_syntax::Span;
 
+/// Create a module with all HTML definitions.
+pub fn module() -> Module {
+    let mut html = Scope::deduplicating();
+    html.start_category(Category::Html);
+    html.define_elem::<HtmlElem>();
+    html.define_elem::<FrameElem>();
+    crate::typed::define(&mut html);
+    Module::new("html", html)
+}
+
 /// Produce an HTML document from content.
 ///
 /// This first performs root-level realization and then turns the resulting
@@ -177,12 +193,12 @@ fn handle(
         output.push(HtmlNode::Tag(elem.tag.clone()));
     } else if let Some(elem) = child.to_packed::<HtmlElem>() {
         let mut children = vec![];
-        if let Some(body) = elem.body(styles) {
+        if let Some(body) = elem.body.get_ref(styles) {
             children = html_fragment(engine, body, locator.next(&elem.span()), styles)?;
         }
         let element = HtmlElement {
             tag: elem.tag,
-            attrs: elem.attrs(styles).clone(),
+            attrs: elem.attrs.get_cloned(styles),
             children,
             span: elem.span(),
         };
@@ -198,7 +214,7 @@ fn handle(
         );
     } else if let Some(elem) = child.to_packed::<BoxElem>() {
         // TODO: This is rather incomplete.
-        if let Some(body) = elem.body(styles) {
+        if let Some(body) = elem.body.get_ref(styles) {
             let children =
                 html_fragment(engine, body, locator.next(&elem.span()), styles)?;
             output.push(
@@ -212,7 +228,7 @@ fn handle(
     } else if let Some((elem, body)) =
         child
             .to_packed::<BlockElem>()
-            .and_then(|elem| match elem.body(styles) {
+            .and_then(|elem| match elem.body.get_ref(styles) {
                 Some(BlockBody::Content(body)) => Some((elem, body)),
                 _ => None,
             })
@@ -233,12 +249,12 @@ fn handle(
         output.push(HtmlElement::new(tag::br).spanned(elem.span()).into());
     } else if let Some(elem) = child.to_packed::<SmartQuoteElem>() {
         output.push(HtmlNode::text(
-            if elem.double(styles) { '"' } else { '\'' },
+            if elem.double.get(styles) { '"' } else { '\'' },
             child.span(),
         ));
     } else if let Some(elem) = child.to_packed::<FrameElem>() {
         let locator = locator.next(&elem.span());
-        let style = TargetElem::set_target(Target::Paged).wrap();
+        let style = TargetElem::target.set(Target::Paged).wrap();
         let frame = (engine.routines.layout_frame)(
             engine,
             &elem.body,
@@ -248,7 +264,7 @@ fn handle(
         )?;
         output.push(HtmlNode::Frame(HtmlFrame {
             inner: frame,
-            text_size: TextElem::size_in(styles),
+            text_size: styles.resolve(TextElem::size),
         }));
     } else {
         engine.sink.warn(warning!(

crates/typst-html/src/rules.rs

@@ -0,0 +1,411 @@
+use std::num::NonZeroUsize;
+
+use ecow::{eco_format, EcoVec};
+use typst_library::diag::warning;
+use typst_library::foundations::{
+    Content, NativeElement, NativeRuleMap, ShowFn, StyleChain, Target,
+};
+use typst_library::html::{attr, tag, HtmlAttrs, HtmlElem, HtmlTag};
+use typst_library::introspection::{Counter, Locator};
+use typst_library::layout::resolve::{table_to_cellgrid, Cell, CellGrid, Entry};
+use typst_library::layout::OuterVAlignment;
+use typst_library::model::{
+    Attribution, CiteElem, CiteGroup, Destination, EmphElem, EnumElem, FigureCaption,
+    FigureElem, HeadingElem, LinkElem, LinkTarget, ListElem, ParbreakElem, QuoteElem,
+    RefElem, StrongElem, TableCell, TableElem, TermsElem,
+};
+use typst_library::text::{
+    HighlightElem, LinebreakElem, OverlineElem, RawElem, RawLine, SpaceElem, StrikeElem,
+    SubElem, SuperElem, UnderlineElem,
+};
+
+/// Register show rules for the [HTML target](Target::Html).
+pub fn register(rules: &mut NativeRuleMap) {
+    use Target::Html;
+
+    // Model.
+    rules.register(Html, STRONG_RULE);
+    rules.register(Html, EMPH_RULE);
+    rules.register(Html, LIST_RULE);
+    rules.register(Html, ENUM_RULE);
+    rules.register(Html, TERMS_RULE);
+    rules.register(Html, LINK_RULE);
+    rules.register(Html, HEADING_RULE);
+    rules.register(Html, FIGURE_RULE);
+    rules.register(Html, FIGURE_CAPTION_RULE);
+    rules.register(Html, QUOTE_RULE);
+    rules.register(Html, REF_RULE);
+    rules.register(Html, CITE_GROUP_RULE);
+    rules.register(Html, TABLE_RULE);
+
+    // Text.
+    rules.register(Html, SUB_RULE);
+    rules.register(Html, SUPER_RULE);
+    rules.register(Html, UNDERLINE_RULE);
+    rules.register(Html, OVERLINE_RULE);
+    rules.register(Html, STRIKE_RULE);
+    rules.register(Html, HIGHLIGHT_RULE);
+    rules.register(Html, RAW_RULE);
+    rules.register(Html, RAW_LINE_RULE);
+}
+
+const STRONG_RULE: ShowFn<StrongElem> = |elem, _, _| {
+    Ok(HtmlElem::new(tag::strong)
+        .with_body(Some(elem.body.clone()))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const EMPH_RULE: ShowFn<EmphElem> = |elem, _, _| {
+    Ok(HtmlElem::new(tag::em)
+        .with_body(Some(elem.body.clone()))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const LIST_RULE: ShowFn<ListElem> = |elem, _, styles| {
+    Ok(HtmlElem::new(tag::ul)
+        .with_body(Some(Content::sequence(elem.children.iter().map(|item| {
+            // Text in wide lists shall always turn into paragraphs.
+            let mut body = item.body.clone();
+            if !elem.tight.get(styles) {
+                body += ParbreakElem::shared();
+            }
+            HtmlElem::new(tag::li)
+                .with_body(Some(body))
+                .pack()
+                .spanned(item.span())
+        }))))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const ENUM_RULE: ShowFn<EnumElem> = |elem, _, styles| {
+    let mut ol = HtmlElem::new(tag::ol);
+
+    if elem.reversed.get(styles) {
+        ol = ol.with_attr(attr::reversed, "reversed");
+    }
+
+    if let Some(n) = elem.start.get(styles).custom() {
+        ol = ol.with_attr(attr::start, eco_format!("{n}"));
+    }
+
+    let body = Content::sequence(elem.children.iter().map(|item| {
+        let mut li = HtmlElem::new(tag::li);
+        if let Some(nr) = item.number.get(styles) {
+            li = li.with_attr(attr::value, eco_format!("{nr}"));
+        }
+        // Text in wide enums shall always turn into paragraphs.
+        let mut body = item.body.clone();
+        if !elem.tight.get(styles) {
+            body += ParbreakElem::shared();
+        }
+        li.with_body(Some(body)).pack().spanned(item.span())
+    }));
+
+    Ok(ol.with_body(Some(body)).pack().spanned(elem.span()))
+};
+
+const TERMS_RULE: ShowFn<TermsElem> = |elem, _, styles| {
+    Ok(HtmlElem::new(tag::dl)
+        .with_body(Some(Content::sequence(elem.children.iter().flat_map(|item| {
+            // Text in wide term lists shall always turn into paragraphs.
+            let mut description = item.description.clone();
+            if !elem.tight.get(styles) {
+                description += ParbreakElem::shared();
+            }
+
+            [
+                HtmlElem::new(tag::dt)
+                    .with_body(Some(item.term.clone()))
+                    .pack()
+                    .spanned(item.term.span()),
+                HtmlElem::new(tag::dd)
+                    .with_body(Some(description))
+                    .pack()
+                    .spanned(item.description.span()),
+            ]
+        }))))
+        .pack())
+};
+
+const LINK_RULE: ShowFn<LinkElem> = |elem, engine, _| {
+    let body = elem.body.clone();
+    Ok(if let LinkTarget::Dest(Destination::Url(url)) = &elem.dest {
+        HtmlElem::new(tag::a)
+            .with_attr(attr::href, url.clone().into_inner())
+            .with_body(Some(body))
+            .pack()
+            .spanned(elem.span())
+    } else {
+        engine.sink.warn(warning!(
+            elem.span(),
+            "non-URL links are not yet supported by HTML export"
+        ));
+        body
+    })
+};
+
+const HEADING_RULE: ShowFn<HeadingElem> = |elem, engine, styles| {
+    let span = elem.span();
+
+    let mut realized = elem.body.clone();
+    if let Some(numbering) = elem.numbering.get_ref(styles).as_ref() {
+        let location = elem.location().unwrap();
+        let numbering = Counter::of(HeadingElem::ELEM)
+            .display_at_loc(engine, location, styles, numbering)?
+            .spanned(span);
+        realized = numbering + SpaceElem::shared().clone() + realized;
+    }
+
+    // HTML's h1 is closer to a title element. There should only be one.
+    // Meanwhile, a level 1 Typst heading is a section heading. For this
+    // reason, levels are offset by one: A Typst level 1 heading becomes
+    // a `<h2>`.
+    let level = elem.resolve_level(styles).get();
+    Ok(if level >= 6 {
+        engine.sink.warn(warning!(
+            span,
+            "heading of level {} was transformed to \
+             <div role=\"heading\" aria-level=\"{}\">, which is not \
+             supported by all assistive technology",
+            level, level + 1;
+            hint: "HTML only supports <h1> to <h6>, not <h{}>", level + 1;
+            hint: "you may want to restructure your document so that \
+                   it doesn't contain deep headings"
+        ));
+        HtmlElem::new(tag::div)
+            .with_body(Some(realized))
+            .with_attr(attr::role, "heading")
+            .with_attr(attr::aria_level, eco_format!("{}", level + 1))
+            .pack()
+            .spanned(span)
+    } else {
+        let t = [tag::h2, tag::h3, tag::h4, tag::h5, tag::h6][level - 1];
+        HtmlElem::new(t).with_body(Some(realized)).pack().spanned(span)
+    })
+};
+
+const FIGURE_RULE: ShowFn<FigureElem> = |elem, _, styles| {
+    let span = elem.span();
+    let mut realized = elem.body.clone();
+
+    // Build the caption, if any.
+    if let Some(caption) = elem.caption.get_cloned(styles) {
+        realized = match caption.position.get(styles) {
+            OuterVAlignment::Top => caption.pack() + realized,
+            OuterVAlignment::Bottom => realized + caption.pack(),
+        };
+    }
+
+    // Ensure that the body is considered a paragraph.
+    realized += ParbreakElem::shared().clone().spanned(span);
+
+    Ok(HtmlElem::new(tag::figure)
+        .with_body(Some(realized))
+        .pack()
+        .spanned(span))
+};
+
+const FIGURE_CAPTION_RULE: ShowFn<FigureCaption> = |elem, engine, styles| {
+    Ok(HtmlElem::new(tag::figcaption)
+        .with_body(Some(elem.realize(engine, styles)?))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const QUOTE_RULE: ShowFn<QuoteElem> = |elem, _, styles| {
+    let span = elem.span();
+    let block = elem.block.get(styles);
+
+    let mut realized = elem.body.clone();
+
+    if elem.quotes.get(styles).unwrap_or(!block) {
+        realized = QuoteElem::quoted(realized, styles);
+    }
+
+    let attribution = elem.attribution.get_ref(styles);
+
+    if block {
+        let mut blockquote = HtmlElem::new(tag::blockquote).with_body(Some(realized));
+        if let Some(Attribution::Content(attribution)) = attribution {
+            if let Some(link) = attribution.to_packed::<LinkElem>() {
+                if let LinkTarget::Dest(Destination::Url(url)) = &link.dest {
+                    blockquote =
+                        blockquote.with_attr(attr::cite, url.clone().into_inner());
+                }
+            }
+        }
+
+        realized = blockquote.pack().spanned(span);
+
+        if let Some(attribution) = attribution.as_ref() {
+            realized += attribution.realize(span);
+        }
+    } else if let Some(Attribution::Label(label)) = attribution {
+        realized += SpaceElem::shared().clone();
+        realized += CiteElem::new(*label).pack().spanned(span);
+    }
+
+    Ok(realized)
+};
+
+const REF_RULE: ShowFn<RefElem> = |elem, engine, styles| elem.realize(engine, styles);
+
+const CITE_GROUP_RULE: ShowFn<CiteGroup> = |elem, engine, _| elem.realize(engine);
+
+const TABLE_RULE: ShowFn<TableElem> = |elem, engine, styles| {
+    // The locator is not used by HTML export, so we can just fabricate one.
+    let locator = Locator::root();
+    Ok(show_cellgrid(table_to_cellgrid(elem, engine, locator, styles)?, styles))
+};
+
+fn show_cellgrid(grid: CellGrid, styles: StyleChain) -> Content {
+    let elem = |tag, body| HtmlElem::new(tag).with_body(Some(body)).pack();
+    let mut rows: Vec<_> = grid.entries.chunks(grid.non_gutter_column_count()).collect();
+
+    let tr = |tag, row: &[Entry]| {
+        let row = row
+            .iter()
+            .flat_map(|entry| entry.as_cell())
+            .map(|cell| show_cell(tag, cell, styles));
+        elem(tag::tr, Content::sequence(row))
+    };
+
+    // TODO(subfooters): similarly to headers, take consecutive footers from
+    // the end for 'tfoot'.
+    let footer = grid.footer.map(|ft| {
+        let rows = rows.drain(ft.start..);
+        elem(tag::tfoot, Content::sequence(rows.map(|row| tr(tag::td, row))))
+    });
+
+    // Store all consecutive headers at the start in 'thead'. All remaining
+    // headers are just 'th' rows across the table body.
+    let mut consecutive_header_end = 0;
+    let first_mid_table_header = grid
+        .headers
+        .iter()
+        .take_while(|hd| {
+            let is_consecutive = hd.range.start == consecutive_header_end;
+            consecutive_header_end = hd.range.end;
+            is_consecutive
+        })
+        .count();
+
+    let (y_offset, header) = if first_mid_table_header > 0 {
+        let removed_header_rows =
+            grid.headers.get(first_mid_table_header - 1).unwrap().range.end;
+        let rows = rows.drain(..removed_header_rows);
+
+        (
+            removed_header_rows,
+            Some(elem(tag::thead, Content::sequence(rows.map(|row| tr(tag::th, row))))),
+        )
+    } else {
+        (0, None)
+    };
+
+    // TODO: Consider improving accessibility properties of multi-level headers
+    // inside tables in the future, e.g. indicating which columns they are
+    // relative to and so on. See also:
+    // https://www.w3.org/WAI/tutorials/tables/multi-level/
+    let mut next_header = first_mid_table_header;
+    let mut body =
+        Content::sequence(rows.into_iter().enumerate().map(|(relative_y, row)| {
+            let y = relative_y + y_offset;
+            if let Some(current_header) =
+                grid.headers.get(next_header).filter(|h| h.range.contains(&y))
+            {
+                if y + 1 == current_header.range.end {
+                    next_header += 1;
+                }
+
+                tr(tag::th, row)
+            } else {
+                tr(tag::td, row)
+            }
+        }));
+
+    if header.is_some() || footer.is_some() {
+        body = elem(tag::tbody, body);
+    }
+
+    let content = header.into_iter().chain(core::iter::once(body)).chain(footer);
+    elem(tag::table, Content::sequence(content))
+}
+
+fn show_cell(tag: HtmlTag, cell: &Cell, styles: StyleChain) -> Content {
+    let cell = cell.body.clone();
+    let Some(cell) = cell.to_packed::<TableCell>() else { return cell };
+    let mut attrs = HtmlAttrs::default();
+    let span = |n: NonZeroUsize| (n != NonZeroUsize::MIN).then(|| n.to_string());
+    if let Some(colspan) = span(cell.colspan.get(styles)) {
+        attrs.push(attr::colspan, colspan);
+    }
+    if let Some(rowspan) = span(cell.rowspan.get(styles)) {
+        attrs.push(attr::rowspan, rowspan);
+    }
+    HtmlElem::new(tag)
+        .with_body(Some(cell.body.clone()))
+        .with_attrs(attrs)
+        .pack()
+        .spanned(cell.span())
+}
+
+const SUB_RULE: ShowFn<SubElem> = |elem, _, _| {
+    Ok(HtmlElem::new(tag::sub)
+        .with_body(Some(elem.body.clone()))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const SUPER_RULE: ShowFn<SuperElem> = |elem, _, _| {
+    Ok(HtmlElem::new(tag::sup)
+        .with_body(Some(elem.body.clone()))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const UNDERLINE_RULE: ShowFn<UnderlineElem> = |elem, _, _| {
+    // Note: In modern HTML, `<u>` is not the underline element, but
+    // rather an "Unarticulated Annotation" element (see HTML spec
+    // 4.5.22). Using `text-decoration` instead is recommended by MDN.
+    Ok(HtmlElem::new(tag::span)
+        .with_attr(attr::style, "text-decoration: underline")
+        .with_body(Some(elem.body.clone()))
+        .pack())
+};
+
+const OVERLINE_RULE: ShowFn<OverlineElem> = |elem, _, _| {
+    Ok(HtmlElem::new(tag::span)
+        .with_attr(attr::style, "text-decoration: overline")
+        .with_body(Some(elem.body.clone()))
+        .pack())
+};
+
+const STRIKE_RULE: ShowFn<StrikeElem> =
+    |elem, _, _| Ok(HtmlElem::new(tag::s).with_body(Some(elem.body.clone())).pack());
+
+const HIGHLIGHT_RULE: ShowFn<HighlightElem> =
+    |elem, _, _| Ok(HtmlElem::new(tag::mark).with_body(Some(elem.body.clone())).pack());
+
+const RAW_RULE: ShowFn<RawElem> = |elem, _, styles| {
+    let lines = elem.lines.as_deref().unwrap_or_default();
+
+    let mut seq = EcoVec::with_capacity((2 * lines.len()).saturating_sub(1));
+    for (i, line) in lines.iter().enumerate() {
+        if i != 0 {
+            seq.push(LinebreakElem::shared().clone());
+        }
+
+        seq.push(line.clone().pack());
+    }
+
+    Ok(HtmlElem::new(if elem.block.get(styles) { tag::pre } else { tag::code })
+        .with_body(Some(Content::sequence(seq)))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const RAW_LINE_RULE: ShowFn<RawLine> = |elem, _, _| Ok(elem.body.clone());

crates/typst-html/src/typed.rs

@@ -11,19 +11,20 @@ use bumpalo::Bump;
 use comemo::Tracked;
 use ecow::{eco_format, eco_vec, EcoString};
 use typst_assets::html as data;
-use typst_macros::cast;
-
-use crate::diag::{bail, At, Hint, HintedStrResult, SourceResult};
-use crate::engine::Engine;
-use crate::foundations::{
+use typst_library::diag::{bail, At, Hint, HintedStrResult, SourceResult};
+use typst_library::engine::Engine;
+use typst_library::foundations::{
     Args, Array, AutoValue, CastInfo, Content, Context, Datetime, Dict, Duration,
     FromValue, IntoValue, NativeFuncData, NativeFuncPtr, NoneValue, ParamInfo,
     PositiveF64, Reflect, Scope, Str, Type, Value,
 };
-use crate::html::tag;
-use crate::html::{HtmlAttr, HtmlAttrs, HtmlElem, HtmlTag};
-use crate::layout::{Axes, Axis, Dir, Length};
-use crate::visualize::Color;
+use typst_library::html::tag;
+use typst_library::html::{HtmlAttr, HtmlAttrs, HtmlElem, HtmlTag};
+use typst_library::layout::{Axes, Axis, Dir, Length};
+use typst_library::visualize::Color;
+use typst_macros::cast;
+
+use crate::css;
 
 /// Hook up all typed HTML definitions.
 pub(super) fn define(html: &mut Scope) {
@@ -127,12 +128,12 @@ fn construct(element: &'static data::ElemInfo, args: &mut Args) -> SourceResult<
     let tag = HtmlTag::constant(element.name);
     let mut elem = HtmlElem::new(tag);
     if !attrs.0.is_empty() {
-        elem.push_attrs(attrs);
+        elem.attrs.set(attrs);
     }
 
     if !tag::is_void(tag) {
         let body = args.eat::<Content>()?;
-        elem.push_body(body);
+        elem.body.set(body);
     }
 
     Ok(elem.into_value())
@@ -705,153 +706,6 @@ impl IntoAttr for SourceSize {
     }
 }
 
-/// Conversion from Typst data types into CSS data types.
-///
-/// This can be moved elsewhere once we start supporting more CSS stuff.
-mod css {
-    use std::fmt::{self, Display};
-
-    use typst_utils::Numeric;
-
-    use crate::layout::Length;
-    use crate::visualize::{Color, Hsl, LinearRgb, Oklab, Oklch, Rgb};
-
-    pub fn length(length: Length) -> impl Display {
-        typst_utils::display(move |f| match (length.abs.is_zero(), length.em.is_zero()) {
-            (false, false) => {
-                write!(f, "calc({}pt + {}em)", length.abs.to_pt(), length.em.get())
-            }
-            (true, false) => write!(f, "{}em", length.em.get()),
-            (_, true) => write!(f, "{}pt", length.abs.to_pt()),
-        })
-    }
-
-    pub fn color(color: Color) -> impl Display {
-        typst_utils::display(move |f| match color {
-            Color::Rgb(_) | Color::Cmyk(_) | Color::Luma(_) => rgb(f, color.to_rgb()),
-            Color::Oklab(v) => oklab(f, v),
-            Color::Oklch(v) => oklch(f, v),
-            Color::LinearRgb(v) => linear_rgb(f, v),
-            Color::Hsl(_) | Color::Hsv(_) => hsl(f, color.to_hsl()),
-        })
-    }
-
-    fn oklab(f: &mut fmt::Formatter<'_>, v: Oklab) -> fmt::Result {
-        write!(
-            f,
-            "oklab({} {} {}{})",
-            percent(v.l),
-            number(v.a),
-            number(v.b),
-            alpha(v.alpha)
-        )
-    }
-
-    fn oklch(f: &mut fmt::Formatter<'_>, v: Oklch) -> fmt::Result {
-        write!(
-            f,
-            "oklch({} {} {}deg{})",
-            percent(v.l),
-            number(v.chroma),
-            number(v.hue.into_degrees()),
-            alpha(v.alpha)
-        )
-    }
-
-    fn rgb(f: &mut fmt::Formatter<'_>, v: Rgb) -> fmt::Result {
-        if let Some(v) = rgb_to_8_bit_lossless(v) {
-            let (r, g, b, a) = v.into_components();
-            write!(f, "#{r:02x}{g:02x}{b:02x}")?;
-            if a != u8::MAX {
-                write!(f, "{a:02x}")?;
-            }
-            Ok(())
-        } else {
-            write!(
-                f,
-                "rgb({} {} {}{})",
-                percent(v.red),
-                percent(v.green),
-                percent(v.blue),
-                alpha(v.alpha)
-            )
-        }
-    }
-
-    /// Converts an f32 RGBA color to its 8-bit representation if the result is
-    /// [very close](is_very_close) to the original.
-    fn rgb_to_8_bit_lossless(
-        v: Rgb,
-    ) -> Option<palette::rgb::Rgba<palette::encoding::Srgb, u8>> {
-        let l = v.into_format::<u8, u8>();
-        let h = l.into_format::<f32, f32>();
-        (is_very_close(v.red, h.red)
-            && is_very_close(v.blue, h.blue)
-            && is_very_close(v.green, h.green)
-            && is_very_close(v.alpha, h.alpha))
-        .then_some(l)
-    }
-
-    fn linear_rgb(f: &mut fmt::Formatter<'_>, v: LinearRgb) -> fmt::Result {
-        write!(
-            f,
-            "color(srgb-linear {} {} {}{})",
-            percent(v.red),
-            percent(v.green),
-            percent(v.blue),
-            alpha(v.alpha),
-        )
-    }
-
-    fn hsl(f: &mut fmt::Formatter<'_>, v: Hsl) -> fmt::Result {
-        write!(
-            f,
-            "hsl({}deg {} {}{})",
-            number(v.hue.into_degrees()),
-            percent(v.saturation),
-            percent(v.lightness),
-            alpha(v.alpha),
-        )
-    }
-
-    /// Displays an alpha component if it not 1.
-    fn alpha(value: f32) -> impl Display {
-        typst_utils::display(move |f| {
-            if !is_very_close(value, 1.0) {
-                write!(f, " / {}", percent(value))?;
-            }
-            Ok(())
-        })
-    }
-
-    /// Displays a rounded percentage.
-    ///
-    /// For a percentage, two significant digits after the comma gives us a
-    /// precision of 1/10_000, which is more than 12 bits (see `is_very_close`).
-    fn percent(ratio: f32) -> impl Display {
-        typst_utils::display(move |f| {
-            write!(f, "{}%", typst_utils::round_with_precision(ratio as f64 * 100.0, 2))
-        })
-    }
-
-    /// Rounds a number for display.
-    ///
-    /// For a number between 0 and 1, four significant digits give us a
-    /// precision of 1/10_000, which is more than 12 bits (see `is_very_close`).
-    fn number(value: f32) -> impl Display {
-        typst_utils::round_with_precision(value as f64, 4)
-    }
-
-    /// Whether two component values are close enough that there is no
-    /// difference when encoding them with 12-bit. 12 bit is the highest
-    /// reasonable color bit depth found in the industry.
-    fn is_very_close(a: f32, b: f32) -> bool {
-        const MAX_BIT_DEPTH: u32 = 12;
-        const EPS: f32 = 0.5 / 2_i32.pow(MAX_BIT_DEPTH) as f32;
-        (a - b).abs() < EPS
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;

crates/typst-ide/src/definition.rs

@@ -187,6 +187,6 @@ mod tests {
 
     #[test]
     fn test_definition_std() {
-        test("#table", 1, Side::After).must_be_value(typst::model::TableElem::elem());
+        test("#table", 1, Side::After).must_be_value(typst::model::TableElem::ELEM);
     }
 }

crates/typst-ide/src/tests.rs

@@ -10,7 +10,7 @@ use typst::syntax::package::{PackageSpec, PackageVersion};
 use typst::syntax::{FileId, Source, VirtualPath};
 use typst::text::{Font, FontBook, TextElem, TextSize};
 use typst::utils::{singleton, LazyHash};
-use typst::{Feature, Library, World};
+use typst::{Feature, Library, LibraryExt, World};
 
 use crate::IdeWorld;
 
@@ -171,13 +171,11 @@ fn library() -> Library {
     let mut lib = typst::Library::builder()
         .with_features([Feature::Html].into_iter().collect())
         .build();
+    lib.styles.set(PageElem::width, Smart::Custom(Abs::pt(120.0).into()));
+    lib.styles.set(PageElem::height, Smart::Auto);
     lib.styles
-        .set(PageElem::set_width(Smart::Custom(Abs::pt(120.0).into())));
-    lib.styles.set(PageElem::set_height(Smart::Auto));
-    lib.styles.set(PageElem::set_margin(Margin::splat(Some(Smart::Custom(
-        Abs::pt(10.0).into(),
-    )))));
-    lib.styles.set(TextElem::set_size(TextSize(Abs::pt(10.0).into())));
+        .set(PageElem::margin, Margin::splat(Some(Smart::Custom(Abs::pt(10.0).into()))));
+    lib.styles.set(TextElem::size, TextSize(Abs::pt(10.0).into()));
     lib
 }
 

crates/typst-layout/src/flow/block.rs

@@ -24,15 +24,15 @@ pub fn layout_single_block(
     region: Region,
 ) -> SourceResult<Frame> {
     // Fetch sizing properties.
-    let width = elem.width(styles);
-    let height = elem.height(styles);
-    let inset = elem.inset(styles).unwrap_or_default();
+    let width = elem.width.get(styles);
+    let height = elem.height.get(styles);
+    let inset = elem.inset.resolve(styles).unwrap_or_default();
 
     // Build the pod regions.
     let pod = unbreakable_pod(&width.into(), &height, &inset, styles, region.size);
 
     // Layout the body.
-    let body = elem.body(styles);
+    let body = elem.body.get_ref(styles);
     let mut frame = match body {
         // If we have no body, just create one frame. Its size will be
         // adjusted below.
@@ -73,18 +73,19 @@ pub fn layout_single_block(
     }
 
     // Prepare fill and stroke.
-    let fill = elem.fill(styles);
+    let fill = elem.fill.get_cloned(styles);
     let stroke = elem
-        .stroke(styles)
+        .stroke
+        .resolve(styles)
         .unwrap_or_default()
         .map(|s| s.map(Stroke::unwrap_or_default));
 
     // Only fetch these if necessary (for clipping or filling/stroking).
-    let outset = LazyCell::new(|| elem.outset(styles).unwrap_or_default());
-    let radius = LazyCell::new(|| elem.radius(styles).unwrap_or_default());
+    let outset = LazyCell::new(|| elem.outset.resolve(styles).unwrap_or_default());
+    let radius = LazyCell::new(|| elem.radius.resolve(styles).unwrap_or_default());
 
     // Clip the contents, if requested.
-    if elem.clip(styles) {
+    if elem.clip.get(styles) {
         frame.clip(clip_rect(frame.size(), &radius, &stroke, &outset));
     }
 
@@ -111,9 +112,9 @@ pub fn layout_multi_block(
     regions: Regions,
 ) -> SourceResult<Fragment> {
     // Fetch sizing properties.
-    let width = elem.width(styles);
-    let height = elem.height(styles);
-    let inset = elem.inset(styles).unwrap_or_default();
+    let width = elem.width.get(styles);
+    let height = elem.height.get(styles);
+    let inset = elem.inset.resolve(styles).unwrap_or_default();
 
     // Allocate a small vector for backlogs.
     let mut buf = SmallVec::<[Abs; 2]>::new();
@@ -122,7 +123,7 @@ pub fn layout_multi_block(
     let pod = breakable_pod(&width.into(), &height, &inset, styles, regions, &mut buf);
 
     // Layout the body.
-    let body = elem.body(styles);
+    let body = elem.body.get_ref(styles);
     let mut fragment = match body {
         // If we have no body, just create one frame plus one per backlog
         // region. We create them zero-sized; if necessary, their size will
@@ -188,29 +189,28 @@ pub fn layout_multi_block(
     };
 
     // Prepare fill and stroke.
-    let fill = elem.fill(styles);
+    let fill = elem.fill.get_ref(styles);
     let stroke = elem
-        .stroke(styles)
+        .stroke
+        .resolve(styles)
         .unwrap_or_default()
         .map(|s| s.map(Stroke::unwrap_or_default));
 
     // Only fetch these if necessary (for clipping or filling/stroking).
-    let outset = LazyCell::new(|| elem.outset(styles).unwrap_or_default());
-    let radius = LazyCell::new(|| elem.radius(styles).unwrap_or_default());
+    let outset = LazyCell::new(|| elem.outset.resolve(styles).unwrap_or_default());
+    let radius = LazyCell::new(|| elem.radius.resolve(styles).unwrap_or_default());
 
     // Fetch/compute these outside of the loop.
-    let clip = elem.clip(styles);
+    let clip = elem.clip.get(styles);
     let has_fill_or_stroke = fill.is_some() || stroke.iter().any(Option::is_some);
     let has_inset = !inset.is_zero();
     let is_explicit = matches!(body, None | Some(BlockBody::Content(_)));
 
-    // Skip filling/stroking the first frame if it is empty and a non-empty
-    // one follows.
+    // Skip filling, stroking and labeling the first frame if it is empty and
+    // a non-empty one follows.
     let mut skip_first = false;
     if let [first, rest @ ..] = fragment.as_slice() {
-        skip_first = has_fill_or_stroke
-            && first.is_empty()
-            && rest.iter().any(|frame| !frame.is_empty());
+        skip_first = first.is_empty() && rest.iter().any(|frame| !frame.is_empty());
     }
 
     // Post-process to apply insets, clipping, fills, and strokes.
@@ -242,7 +242,8 @@ pub fn layout_multi_block(
 
     // Assign label to each frame in the fragment.
     if let Some(label) = elem.label() {
-        for frame in fragment.iter_mut() {
+        // Skip empty orphan frames, as a label would make them non-empty.
+        for frame in fragment.iter_mut().skip(if skip_first { 1 } else { 0 }) {
             frame.label(label);
         }
     }

crates/typst-layout/src/flow/collect.rs

@@ -89,7 +89,7 @@ impl<'a> Collector<'a, '_, '_> {
             } else if child.is::<FlushElem>() {
                 self.output.push(Child::Flush);
             } else if let Some(elem) = child.to_packed::<ColbreakElem>() {
-                self.output.push(Child::Break(elem.weak(styles)));
+                self.output.push(Child::Break(elem.weak.get(styles)));
             } else if child.is::<PagebreakElem>() {
                 bail!(
                     child.span(), "pagebreaks are not allowed inside of containers";
@@ -132,7 +132,7 @@ impl<'a> Collector<'a, '_, '_> {
             self.output.push(Child::Tag(&elem.tag));
         }
 
-        let leading = ParElem::leading_in(styles);
+        let leading = styles.resolve(ParElem::leading);
         self.lines(lines, leading, styles);
 
         for (c, _) in &self.children[end..] {
@@ -146,7 +146,9 @@ impl<'a> Collector<'a, '_, '_> {
     /// Collect vertical spacing into a relative or fractional child.
     fn v(&mut self, elem: &'a Packed<VElem>, styles: StyleChain<'a>) {
         self.output.push(match elem.amount {
-            Spacing::Rel(rel) => Child::Rel(rel.resolve(styles), elem.weak(styles) as u8),
+            Spacing::Rel(rel) => {
+                Child::Rel(rel.resolve(styles), elem.weak.get(styles) as u8)
+            }
             Spacing::Fr(fr) => Child::Fr(fr),
         });
     }
@@ -169,8 +171,8 @@ impl<'a> Collector<'a, '_, '_> {
         )?
         .into_frames();
 
-        let spacing = elem.spacing(styles);
-        let leading = elem.leading(styles);
+        let spacing = elem.spacing.resolve(styles);
+        let leading = elem.leading.resolve(styles);
 
         self.output.push(Child::Rel(spacing.into(), 4));
 
@@ -184,8 +186,8 @@ impl<'a> Collector<'a, '_, '_> {
 
     /// Collect laid-out lines.
     fn lines(&mut self, lines: Vec<Frame>, leading: Abs, styles: StyleChain<'a>) {
-        let align = AlignElem::alignment_in(styles).resolve(styles);
-        let costs = TextElem::costs_in(styles);
+        let align = styles.resolve(AlignElem::alignment);
+        let costs = styles.get(TextElem::costs);
 
         // Determine whether to prevent widow and orphans.
         let len = lines.len();
@@ -231,23 +233,23 @@ impl<'a> Collector<'a, '_, '_> {
     /// whether it is breakable.
     fn block(&mut self, elem: &'a Packed<BlockElem>, styles: StyleChain<'a>) {
         let locator = self.locator.next(&elem.span());
-        let align = AlignElem::alignment_in(styles).resolve(styles);
+        let align = styles.resolve(AlignElem::alignment);
         let alone = self.children.len() == 1;
-        let sticky = elem.sticky(styles);
-        let breakable = elem.breakable(styles);
-        let fr = match elem.height(styles) {
+        let sticky = elem.sticky.get(styles);
+        let breakable = elem.breakable.get(styles);
+        let fr = match elem.height.get(styles) {
             Sizing::Fr(fr) => Some(fr),
             _ => None,
         };
 
-        let fallback = LazyCell::new(|| ParElem::spacing_in(styles));
+        let fallback = LazyCell::new(|| styles.resolve(ParElem::spacing));
         let spacing = |amount| match amount {
             Smart::Auto => Child::Rel((*fallback).into(), 4),
             Smart::Custom(Spacing::Rel(rel)) => Child::Rel(rel.resolve(styles), 3),
             Smart::Custom(Spacing::Fr(fr)) => Child::Fr(fr),
         };
 
-        self.output.push(spacing(elem.above(styles)));
+        self.output.push(spacing(elem.above.get(styles)));
 
         if !breakable || fr.is_some() {
             self.output.push(Child::Single(self.boxed(SingleChild {
@@ -272,7 +274,7 @@ impl<'a> Collector<'a, '_, '_> {
             })));
         };
 
-        self.output.push(spacing(elem.below(styles)));
+        self.output.push(spacing(elem.below.get(styles)));
         self.par_situation = ParSituation::Other;
     }
 
@@ -282,13 +284,13 @@ impl<'a> Collector<'a, '_, '_> {
         elem: &'a Packed<PlaceElem>,
         styles: StyleChain<'a>,
     ) -> SourceResult<()> {
-        let alignment = elem.alignment(styles);
+        let alignment = elem.alignment.get(styles);
         let align_x = alignment.map_or(FixedAlignment::Center, |align| {
             align.x().unwrap_or_default().resolve(styles)
         });
         let align_y = alignment.map(|align| align.y().map(|y| y.resolve(styles)));
-        let scope = elem.scope(styles);
-        let float = elem.float(styles);
+        let scope = elem.scope.get(styles);
+        let float = elem.float.get(styles);
 
         match (float, align_y) {
             (true, Smart::Custom(None | Some(FixedAlignment::Center))) => bail!(
@@ -312,8 +314,8 @@ impl<'a> Collector<'a, '_, '_> {
         }
 
         let locator = self.locator.next(&elem.span());
-        let clearance = elem.clearance(styles);
-        let delta = Axes::new(elem.dx(styles), elem.dy(styles)).resolve(styles);
+        let clearance = elem.clearance.resolve(styles);
+        let delta = Axes::new(elem.dx.get(styles), elem.dy.get(styles)).resolve(styles);
         self.output.push(Child::Placed(self.boxed(PlacedChild {
             align_x,
             align_y,
@@ -457,6 +459,7 @@ impl<'a> MultiChild<'a> {
         regions: Regions,
     ) -> SourceResult<(Frame, Option<MultiSpill<'a, 'b>>)> {
         let fragment = self.layout_full(engine, regions)?;
+        let exist_non_empty_frame = fragment.iter().any(|f| !f.is_empty());
 
         // Extract the first frame.
         let mut frames = fragment.into_iter();
@@ -466,6 +469,7 @@ impl<'a> MultiChild<'a> {
         let mut spill = None;
         if frames.next().is_some() {
             spill = Some(MultiSpill {
+                exist_non_empty_frame,
                 multi: self,
                 full: regions.full,
                 first: regions.size.y,
@@ -537,6 +541,7 @@ fn layout_multi_impl(
 /// The spilled remains of a `MultiChild` that broke across two regions.
 #[derive(Debug, Clone)]
 pub struct MultiSpill<'a, 'b> {
+    pub(super) exist_non_empty_frame: bool,
     multi: &'b MultiChild<'a>,
     first: Abs,
     full: Abs,
@@ -631,7 +636,7 @@ impl PlacedChild<'_> {
     pub fn layout(&self, engine: &mut Engine, base: Size) -> SourceResult<Frame> {
         self.cell.get_or_init(base, |base| {
             let align = self.alignment.unwrap_or_else(|| Alignment::CENTER);
-            let aligned = AlignElem::set_alignment(align).wrap();
+            let aligned = AlignElem::alignment.set(align).wrap();
             let styles = self.styles.chain(&aligned);
 
             let mut frame = layout_and_modify(styles, |styles| {

crates/typst-layout/src/flow/compose.rs

@@ -851,7 +851,7 @@ fn layout_line_number_reset(
     config: &Config,
     locator: &mut SplitLocator,
 ) -> SourceResult<Frame> {
-    let counter = Counter::of(ParLineMarker::elem());
+    let counter = Counter::of(ParLineMarker::ELEM);
     let update = CounterUpdate::Set(CounterState::init(false));
     let content = counter.update(Span::detached(), update);
     crate::layout_frame(
@@ -879,7 +879,7 @@ fn layout_line_number(
     locator: &mut SplitLocator,
     numbering: &Numbering,
 ) -> SourceResult<Frame> {
-    let counter = Counter::of(ParLineMarker::elem());
+    let counter = Counter::of(ParLineMarker::ELEM);
     let update = CounterUpdate::Step(NonZeroUsize::ONE);
     let numbering = Smart::Custom(numbering.clone());
 

crates/typst-layout/src/flow/distribute.rs

@@ -283,6 +283,13 @@ impl<'a, 'b> Distributor<'a, 'b, '_, '_, '_> {
 
         // Lay out the block.
         let (frame, spill) = multi.layout(self.composer.engine, self.regions)?;
+        if frame.is_empty() && spill.as_ref().is_some_and(|s| s.exist_non_empty_frame) {
+            // If the first frame is empty, but there are non-empty frames in
+            // the spill, the whole child should be put in the next region to
+            // avoid any invisible orphans at the end of this region.
+            return Err(Stop::Finish(false));
+        }
+
         self.frame(frame, multi.align, multi.sticky, true)?;
 
         // If the block didn't fully fit into the current region, save it into

crates/typst-layout/src/flow/mod.rs

@@ -98,8 +98,8 @@ pub fn layout_columns(
         locator.track(),
         styles,
         regions,
-        elem.count(styles),
-        elem.gutter(styles),
+        elem.count.get(styles),
+        elem.gutter.resolve(styles),
     )
 }
 
@@ -251,22 +251,22 @@ fn configuration<'x>(
 
             let gutter = column_gutter.relative_to(regions.base().x);
             let width = (regions.size.x - gutter * (count - 1) as f64) / count as f64;
-            let dir = TextElem::dir_in(shared);
+            let dir = shared.resolve(TextElem::dir);
             ColumnConfig { count, width, gutter, dir }
         },
         footnote: FootnoteConfig {
-            separator: FootnoteEntry::separator_in(shared),
-            clearance: FootnoteEntry::clearance_in(shared),
-            gap: FootnoteEntry::gap_in(shared),
+            separator: shared.get_cloned(FootnoteEntry::separator),
+            clearance: shared.resolve(FootnoteEntry::clearance),
+            gap: shared.resolve(FootnoteEntry::gap),
             expand: regions.expand.x,
         },
         line_numbers: (mode == FlowMode::Root).then(|| LineNumberConfig {
-            scope: ParLine::numbering_scope_in(shared),
+            scope: shared.get(ParLine::numbering_scope),
             default_clearance: {
-                let width = if PageElem::flipped_in(shared) {
-                    PageElem::height_in(shared)
+                let width = if shared.get(PageElem::flipped) {
+                    shared.resolve(PageElem::height)
                 } else {
-                    PageElem::width_in(shared)
+                    shared.resolve(PageElem::width)
                 };
 
                 // Clamp below is safe (min <= max): if the font size is

crates/typst-layout/src/grid/layouter.rs

@@ -249,7 +249,7 @@ impl<'a> GridLayouter<'a> {
             rowspans: vec![],
             finished: vec![],
             finished_header_rows: vec![],
-            is_rtl: TextElem::dir_in(styles) == Dir::RTL,
+            is_rtl: styles.resolve(TextElem::dir) == Dir::RTL,
             repeating_headers: vec![],
             upcoming_headers: &grid.headers,
             pending_headers: Default::default(),

crates/typst-layout/src/image.rs

@@ -28,7 +28,7 @@ pub fn layout_image(
     // Take the format that was explicitly defined, or parse the extension,
     // or try to detect the format.
     let Derived { source, derived: loaded } = &elem.source;
-    let format = match elem.format(styles) {
+    let format = match elem.format.get(styles) {
         Smart::Custom(v) => v,
         Smart::Auto => determine_format(source, &loaded.data).at(span)?,
     };
@@ -55,7 +55,7 @@ pub fn layout_image(
             RasterImage::new(
                 loaded.data.clone(),
                 format,
-                elem.icc(styles).as_ref().map(|icc| icc.derived.clone()),
+                elem.icc.get_ref(styles).as_ref().map(|icc| icc.derived.clone()),
             )
             .at(span)?,
         ),
@@ -69,7 +69,7 @@ pub fn layout_image(
         ),
     };
 
-    let image = Image::new(kind, elem.alt(styles), elem.scaling(styles));
+    let image = Image::new(kind, elem.alt.get_cloned(styles), elem.scaling.get(styles));
 
     // Determine the image's pixel aspect ratio.
     let pxw = image.width();
@@ -106,7 +106,7 @@ pub fn layout_image(
     };
 
     // Compute the actual size of the fitted image.
-    let fit = elem.fit(styles);
+    let fit = elem.fit.get(styles);
     let fitted = match fit {
         ImageFit::Cover | ImageFit::Contain => {
             if wide == (fit == ImageFit::Contain) {

crates/typst-layout/src/inline/box.rs

@@ -21,15 +21,15 @@ pub fn layout_box(
     region: Size,
 ) -> SourceResult<Frame> {
     // Fetch sizing properties.
-    let width = elem.width(styles);
-    let height = elem.height(styles);
-    let inset = elem.inset(styles).unwrap_or_default();
+    let width = elem.width.get(styles);
+    let height = elem.height.get(styles);
+    let inset = elem.inset.resolve(styles).unwrap_or_default();
 
     // Build the pod region.
     let pod = unbreakable_pod(&width, &height.into(), &inset, styles, region);
 
     // Layout the body.
-    let mut frame = match elem.body(styles) {
+    let mut frame = match elem.body.get_ref(styles) {
         // If we have no body, just create an empty frame. If necessary,
         // its size will be adjusted below.
         None => Frame::hard(Size::zero()),
@@ -50,18 +50,19 @@ pub fn layout_box(
     }
 
     // Prepare fill and stroke.
-    let fill = elem.fill(styles);
+    let fill = elem.fill.get_cloned(styles);
     let stroke = elem
-        .stroke(styles)
+        .stroke
+        .resolve(styles)
         .unwrap_or_default()
         .map(|s| s.map(Stroke::unwrap_or_default));
 
     // Only fetch these if necessary (for clipping or filling/stroking).
-    let outset = LazyCell::new(|| elem.outset(styles).unwrap_or_default());
-    let radius = LazyCell::new(|| elem.radius(styles).unwrap_or_default());
+    let outset = LazyCell::new(|| elem.outset.resolve(styles).unwrap_or_default());
+    let radius = LazyCell::new(|| elem.radius.resolve(styles).unwrap_or_default());
 
     // Clip the contents, if requested.
-    if elem.clip(styles) {
+    if elem.clip.get(styles) {
         frame.clip(clip_rect(frame.size(), &radius, &stroke, &outset));
     }
 
@@ -78,7 +79,7 @@ pub fn layout_box(
     // Apply baseline shift. Do this after setting the size and applying the
     // inset, so that a relative shift is resolved relative to the final
     // height.
-    let shift = elem.baseline(styles).relative_to(frame.height());
+    let shift = elem.baseline.resolve(styles).relative_to(frame.height());
     if !shift.is_zero() {
         frame.set_baseline(frame.baseline() - shift);
     }

crates/typst-layout/src/inline/collect.rs

@@ -144,7 +144,7 @@ pub fn collect<'a>(
             collector.push_text(" ", styles);
         } else if let Some(elem) = child.to_packed::<TextElem>() {
             collector.build_text(styles, |full| {
-                let dir = TextElem::dir_in(styles);
+                let dir = styles.resolve(TextElem::dir);
                 if dir != config.dir {
                     // Insert "Explicit Directional Embedding".
                     match dir {
@@ -154,7 +154,7 @@ pub fn collect<'a>(
                     }
                 }
 
-                if let Some(case) = TextElem::case_in(styles) {
+                if let Some(case) = styles.get(TextElem::case) {
                     full.push_str(&case.apply(&elem.text));
                 } else {
                     full.push_str(&elem.text);
@@ -174,20 +174,22 @@ pub fn collect<'a>(
                 Spacing::Fr(fr) => Item::Fractional(fr, None),
                 Spacing::Rel(rel) => Item::Absolute(
                     rel.resolve(styles).relative_to(region.x),
-                    elem.weak(styles),
+                    elem.weak.get(styles),
                 ),
             });
         } else if let Some(elem) = child.to_packed::<LinebreakElem>() {
-            collector
-                .push_text(if elem.justify(styles) { "\u{2028}" } else { "\n" }, styles);
+            collector.push_text(
+                if elem.justify.get(styles) { "\u{2028}" } else { "\n" },
+                styles,
+            );
         } else if let Some(elem) = child.to_packed::<SmartQuoteElem>() {
-            let double = elem.double(styles);
-            if elem.enabled(styles) {
+            let double = elem.double.get(styles);
+            if elem.enabled.get(styles) {
                 let quotes = SmartQuotes::get(
-                    elem.quotes(styles),
-                    TextElem::lang_in(styles),
-                    TextElem::region_in(styles),
-                    elem.alternative(styles),
+                    elem.quotes.get_ref(styles),
+                    styles.get(TextElem::lang),
+                    styles.get(TextElem::region),
+                    elem.alternative.get(styles),
                 );
                 let before =
                     collector.full.chars().rev().find(|&c| !is_default_ignorable(c));
@@ -215,7 +217,7 @@ pub fn collect<'a>(
             collector.push_item(Item::Skip(POP_ISOLATE));
         } else if let Some(elem) = child.to_packed::<BoxElem>() {
             let loc = locator.next(&elem.span());
-            if let Sizing::Fr(v) = elem.width(styles) {
+            if let Sizing::Fr(v) = elem.width.get(styles) {
                 collector.push_item(Item::Fractional(v, Some((elem, loc, styles))));
             } else {
                 let mut frame = layout_and_modify(styles, |styles| {

crates/typst-layout/src/inline/line.rs

@@ -2,6 +2,7 @@ use std::fmt::{self, Debug, Formatter};
 use std::ops::{Deref, DerefMut};
 
 use typst_library::engine::Engine;
+use typst_library::foundations::Resolve;
 use typst_library::introspection::{SplitLocator, Tag};
 use typst_library::layout::{Abs, Dir, Em, Fr, Frame, FrameItem, Point};
 use typst_library::model::ParLineMarker;
@@ -418,10 +419,11 @@ pub fn apply_shift<'a>(
     frame: &mut Frame,
     styles: StyleChain,
 ) {
-    let mut baseline = TextElem::baseline_in(styles);
+    let mut baseline = styles.resolve(TextElem::baseline);
     let mut compensation = Abs::zero();
-    if let Some(scripts) = TextElem::shift_settings_in(styles) {
-        let font_metrics = TextElem::font_in(styles)
+    if let Some(scripts) = styles.get_ref(TextElem::shift_settings) {
+        let font_metrics = styles
+            .get_ref(TextElem::font)
             .into_iter()
             .find_map(|family| {
                 world
@@ -462,7 +464,7 @@ pub fn commit(
     if let Some(Item::Text(text)) = line.items.first() {
         if let Some(glyph) = text.glyphs.first() {
             if !text.dir.is_positive()
-                && TextElem::overhang_in(text.styles)
+                && text.styles.get(TextElem::overhang)
                 && (line.items.len() > 1 || text.glyphs.len() > 1)
             {
                 let amount = overhang(glyph.c) * glyph.x_advance.at(glyph.size);
@@ -476,7 +478,7 @@ pub fn commit(
     if let Some(Item::Text(text)) = line.items.last() {
         if let Some(glyph) = text.glyphs.last() {
             if text.dir.is_positive()
-                && TextElem::overhang_in(text.styles)
+                && text.styles.get(TextElem::overhang)
                 && (line.items.len() > 1 || text.glyphs.len() > 1)
             {
                 let amount = overhang(glyph.c) * glyph.x_advance.at(glyph.size);

crates/typst-layout/src/inline/linebreak.rs

@@ -846,7 +846,9 @@ fn hyphenate_at(p: &Preparation, offset: usize) -> bool {
     p.config.hyphenate.unwrap_or_else(|| {
         let (_, item) = p.get(offset);
         match item.text() {
-            Some(text) => TextElem::hyphenate_in(text.styles).unwrap_or(p.config.justify),
+            Some(text) => {
+                text.styles.get(TextElem::hyphenate).unwrap_or(p.config.justify)
+            }
             None => false,
         }
     })
@@ -857,7 +859,7 @@ fn lang_at(p: &Preparation, offset: usize) -> Option<hypher::Lang> {
     let lang = p.config.lang.or_else(|| {
         let (_, item) = p.get(offset);
         let styles = item.text()?.styles;
-        Some(TextElem::lang_in(styles))
+        Some(styles.get(TextElem::lang))
     })?;
 
     let bytes = lang.as_str().as_bytes().try_into().ok()?;

crates/typst-layout/src/inline/mod.rs

@@ -14,7 +14,7 @@ pub use self::shaping::create_shape_plan;
 use comemo::{Track, Tracked, TrackedMut};
 use typst_library::diag::SourceResult;
 use typst_library::engine::{Engine, Route, Sink, Traced};
-use typst_library::foundations::{Packed, Resolve, Smart, StyleChain};
+use typst_library::foundations::{Packed, Smart, StyleChain};
 use typst_library::introspection::{Introspector, Locator, LocatorLink, SplitLocator};
 use typst_library::layout::{Abs, AlignElem, Dir, FixedAlignment, Fragment, Size};
 use typst_library::model::{
@@ -113,10 +113,10 @@ fn layout_par_impl(
         expand,
         Some(situation),
         &ConfigBase {
-            justify: elem.justify(styles),
-            linebreaks: elem.linebreaks(styles),
-            first_line_indent: elem.first_line_indent(styles),
-            hanging_indent: elem.hanging_indent(styles),
+            justify: elem.justify.get(styles),
+            linebreaks: elem.linebreaks.get(styles),
+            first_line_indent: elem.first_line_indent.get(styles),
+            hanging_indent: elem.hanging_indent.resolve(styles),
         },
     )
 }
@@ -139,10 +139,10 @@ pub fn layout_inline<'a>(
         expand,
         None,
         &ConfigBase {
-            justify: ParElem::justify_in(shared),
-            linebreaks: ParElem::linebreaks_in(shared),
-            first_line_indent: ParElem::first_line_indent_in(shared),
-            hanging_indent: ParElem::hanging_indent_in(shared),
+            justify: shared.get(ParElem::justify),
+            linebreaks: shared.get(ParElem::linebreaks),
+            first_line_indent: shared.get(ParElem::first_line_indent),
+            hanging_indent: shared.resolve(ParElem::hanging_indent),
         },
     )
 }
@@ -184,8 +184,8 @@ fn configuration(
     situation: Option<ParSituation>,
 ) -> Config {
     let justify = base.justify;
-    let font_size = TextElem::size_in(shared);
-    let dir = TextElem::dir_in(shared);
+    let font_size = shared.resolve(TextElem::size);
+    let dir = shared.resolve(TextElem::dir);
 
     Config {
         justify,
@@ -207,7 +207,7 @@ fn configuration(
                     Some(ParSituation::Other) => all,
                     None => false,
                 }
-                && AlignElem::alignment_in(shared).resolve(shared).x == dir.start().into()
+                && shared.resolve(AlignElem::alignment).x == dir.start().into()
             {
                 amount.at(font_size)
             } else {
@@ -219,26 +219,26 @@ fn configuration(
         } else {
             Abs::zero()
         },
-        numbering_marker: ParLine::numbering_in(shared).map(|numbering| {
+        numbering_marker: shared.get_cloned(ParLine::numbering).map(|numbering| {
             Packed::new(ParLineMarker::new(
                 numbering,
-                ParLine::number_align_in(shared),
-                ParLine::number_margin_in(shared),
+                shared.get(ParLine::number_align),
+                shared.get(ParLine::number_margin),
                 // Delay resolving the number clearance until line numbers are
                 // laid out to avoid inconsistent spacing depending on varying
                 // font size.
-                ParLine::number_clearance_in(shared),
+                shared.get(ParLine::number_clearance),
             ))
         }),
-        align: AlignElem::alignment_in(shared).fix(dir).x,
+        align: shared.get(AlignElem::alignment).fix(dir).x,
         font_size,
         dir,
-        hyphenate: shared_get(children, shared, TextElem::hyphenate_in)
+        hyphenate: shared_get(children, shared, |s| s.get(TextElem::hyphenate))
             .map(|uniform| uniform.unwrap_or(justify)),
-        lang: shared_get(children, shared, TextElem::lang_in),
-        fallback: TextElem::fallback_in(shared),
-        cjk_latin_spacing: TextElem::cjk_latin_spacing_in(shared).is_auto(),
-        costs: TextElem::costs_in(shared),
+        lang: shared_get(children, shared, |s| s.get(TextElem::lang)),
+        fallback: shared.get(TextElem::fallback),
+        cjk_latin_spacing: shared.get(TextElem::cjk_latin_spacing).is_auto(),
+        costs: shared.get(TextElem::costs),
     }
 }
 
@@ -314,7 +314,7 @@ fn shared_get<T: PartialEq>(
 /// When we support some kind of more general ancestry mechanism, this can
 /// become more elegant.
 fn in_list(styles: StyleChain) -> bool {
-    ListElem::depth_in(styles).0 > 0
-        || !EnumElem::parents_in(styles).is_empty()
-        || TermsElem::within_in(styles)
+    styles.get(ListElem::depth).0 > 0
+        || !styles.get_cloned(EnumElem::parents).is_empty()
+        || styles.get(TermsElem::within)
 }

crates/typst-layout/src/inline/shaping.rs

@@ -223,12 +223,12 @@ impl<'a> ShapedText<'a> {
         let mut frame = Frame::soft(size);
         frame.set_baseline(top);
 
-        let size = TextElem::size_in(self.styles);
-        let shift = TextElem::baseline_in(self.styles);
-        let decos = TextElem::deco_in(self.styles);
-        let fill = TextElem::fill_in(self.styles);
-        let stroke = TextElem::stroke_in(self.styles);
-        let span_offset = TextElem::span_offset_in(self.styles);
+        let size = self.styles.resolve(TextElem::size);
+        let shift = self.styles.resolve(TextElem::baseline);
+        let decos = self.styles.get_cloned(TextElem::deco);
+        let fill = self.styles.get_ref(TextElem::fill);
+        let stroke = self.styles.resolve(TextElem::stroke);
+        let span_offset = self.styles.get(TextElem::span_offset);
 
         for ((font, y_offset, glyph_size), group) in self
             .glyphs
@@ -340,9 +340,9 @@ impl<'a> ShapedText<'a> {
         let mut top = Abs::zero();
         let mut bottom = Abs::zero();
 
-        let size = TextElem::size_in(self.styles);
-        let top_edge = TextElem::top_edge_in(self.styles);
-        let bottom_edge = TextElem::bottom_edge_in(self.styles);
+        let size = self.styles.resolve(TextElem::size);
+        let top_edge = self.styles.get(TextElem::top_edge);
+        let bottom_edge = self.styles.get(TextElem::bottom_edge);
 
         // Expand top and bottom by reading the font's vertical metrics.
         let mut expand = |font: &Font, bounds: TextEdgeBounds| {
@@ -486,7 +486,7 @@ impl<'a> ShapedText<'a> {
             // that subtracting either of the endpoints by self.base doesn't
             // underflow. See <https://github.com/typst/typst/issues/2283>.
             .unwrap_or_else(|| self.base..self.base);
-            let size = TextElem::size_in(self.styles);
+            let size = self.styles.resolve(TextElem::size);
             self.width += x_advance.at(size);
             let glyph = ShapedGlyph {
                 font,
@@ -603,9 +603,9 @@ pub fn shape_range<'a>(
     range: Range,
     styles: StyleChain<'a>,
 ) {
-    let script = TextElem::script_in(styles);
-    let lang = TextElem::lang_in(styles);
-    let region = TextElem::region_in(styles);
+    let script = styles.get(TextElem::script);
+    let lang = styles.get(TextElem::lang);
+    let region = styles.get(TextElem::region);
     let mut process = |range: Range, level: BidiLevel| {
         let dir = if level.is_ltr() { Dir::LTR } else { Dir::RTL };
         let shaped =
@@ -669,8 +669,8 @@ fn shape<'a>(
     lang: Lang,
     region: Option<Region>,
 ) -> ShapedText<'a> {
-    let size = TextElem::size_in(styles);
-    let shift_settings = TextElem::shift_settings_in(styles);
+    let size = styles.resolve(TextElem::size);
+    let shift_settings = styles.get(TextElem::shift_settings);
     let mut ctx = ShapingContext {
         engine,
         size,
@@ -679,7 +679,7 @@ fn shape<'a>(
         styles,
         variant: variant(styles),
         features: features(styles),
-        fallback: TextElem::fallback_in(styles),
+        fallback: styles.get(TextElem::fallback),
         dir,
         shift_settings,
     };
@@ -783,7 +783,7 @@ fn shape_segment<'a>(
     let mut buffer = UnicodeBuffer::new();
     buffer.push_str(text);
     buffer.set_language(language(ctx.styles));
-    if let Some(script) = TextElem::script_in(ctx.styles).custom().and_then(|script| {
+    if let Some(script) = ctx.styles.get(TextElem::script).custom().and_then(|script| {
         rustybuzz::Script::from_iso15924_tag(Tag::from_bytes(script.as_bytes()))
     }) {
         buffer.set_script(script)
@@ -1073,8 +1073,11 @@ fn shape_tofus(ctx: &mut ShapingContext, base: usize, text: &str, font: Font) {
 
 /// Apply tracking and spacing to the shaped glyphs.
 fn track_and_space(ctx: &mut ShapingContext) {
-    let tracking = Em::from_abs(TextElem::tracking_in(ctx.styles), ctx.size);
-    let spacing = TextElem::spacing_in(ctx.styles).map(|abs| Em::from_abs(abs, ctx.size));
+    let tracking = Em::from_abs(ctx.styles.resolve(TextElem::tracking), ctx.size);
+    let spacing = ctx
+        .styles
+        .resolve(TextElem::spacing)
+        .map(|abs| Em::from_abs(abs, ctx.size));
 
     let mut glyphs = ctx.glyphs.iter_mut().peekable();
     while let Some(glyph) = glyphs.next() {

crates/typst-layout/src/lib.rs

@@ -10,21 +10,11 @@ mod modifiers;
 mod pad;
 mod pages;
 mod repeat;
+mod rules;
 mod shapes;
 mod stack;
 mod transforms;
 
-pub use self::flow::{layout_columns, layout_fragment, layout_frame};
-pub use self::grid::{layout_grid, layout_table};
-pub use self::image::layout_image;
-pub use self::lists::{layout_enum, layout_list};
-pub use self::math::{layout_equation_block, layout_equation_inline};
-pub use self::pad::layout_pad;
+pub use self::flow::{layout_fragment, layout_frame};
 pub use self::pages::layout_document;
-pub use self::repeat::layout_repeat;
-pub use self::shapes::{
-    layout_circle, layout_curve, layout_ellipse, layout_line, layout_path,
-    layout_polygon, layout_rect, layout_square,
-};
-pub use self::stack::layout_stack;
-pub use self::transforms::{layout_move, layout_rotate, layout_scale, layout_skew};
+pub use self::rules::register;

crates/typst-layout/src/lists.rs

@@ -20,20 +20,21 @@ pub fn layout_list(
     styles: StyleChain,
     regions: Regions,
 ) -> SourceResult<Fragment> {
-    let indent = elem.indent(styles);
-    let body_indent = elem.body_indent(styles);
-    let tight = elem.tight(styles);
-    let gutter = elem.spacing(styles).unwrap_or_else(|| {
+    let indent = elem.indent.get(styles);
+    let body_indent = elem.body_indent.get(styles);
+    let tight = elem.tight.get(styles);
+    let gutter = elem.spacing.get(styles).unwrap_or_else(|| {
         if tight {
-            ParElem::leading_in(styles).into()
+            styles.get(ParElem::leading)
         } else {
-            ParElem::spacing_in(styles).into()
+            styles.get(ParElem::spacing)
         }
     });
 
-    let Depth(depth) = ListElem::depth_in(styles);
+    let Depth(depth) = styles.get(ListElem::depth);
     let marker = elem
-        .marker(styles)
+        .marker
+        .get_ref(styles)
         .resolve(engine, styles, depth)?
         // avoid '#set align' interference with the list
         .aligned(HAlignment::Start + VAlignment::Top);
@@ -52,7 +53,7 @@ pub fn layout_list(
         cells.push(Cell::new(marker.clone(), locator.next(&marker.span())));
         cells.push(Cell::new(Content::empty(), locator.next(&())));
         cells.push(Cell::new(
-            body.styled(ListElem::set_depth(Depth(1))),
+            body.set(ListElem::depth, Depth(1)),
             locator.next(&item.body.span()),
         ));
     }
@@ -81,40 +82,40 @@ pub fn layout_enum(
     styles: StyleChain,
     regions: Regions,
 ) -> SourceResult<Fragment> {
-    let numbering = elem.numbering(styles);
-    let reversed = elem.reversed(styles);
-    let indent = elem.indent(styles);
-    let body_indent = elem.body_indent(styles);
-    let tight = elem.tight(styles);
-    let gutter = elem.spacing(styles).unwrap_or_else(|| {
+    let numbering = elem.numbering.get_ref(styles);
+    let reversed = elem.reversed.get(styles);
+    let indent = elem.indent.get(styles);
+    let body_indent = elem.body_indent.get(styles);
+    let tight = elem.tight.get(styles);
+    let gutter = elem.spacing.get(styles).unwrap_or_else(|| {
         if tight {
-            ParElem::leading_in(styles).into()
+            styles.get(ParElem::leading)
         } else {
-            ParElem::spacing_in(styles).into()
+            styles.get(ParElem::spacing)
         }
     });
 
     let mut cells = vec![];
     let mut locator = locator.split();
-    let mut number = elem.start(styles).unwrap_or_else(|| {
+    let mut number = elem.start.get(styles).unwrap_or_else(|| {
         if reversed {
             elem.children.len() as u64
         } else {
             1
         }
     });
-    let mut parents = EnumElem::parents_in(styles);
+    let mut parents = styles.get_cloned(EnumElem::parents);
 
-    let full = elem.full(styles);
+    let full = elem.full.get(styles);
 
     // Horizontally align based on the given respective parameter.
     // Vertically align to the top to avoid inheriting `horizon` or `bottom`
     // alignment from the context and having the number be displaced in
     // relation to the item it refers to.
-    let number_align = elem.number_align(styles);
+    let number_align = elem.number_align.get(styles);
 
     for item in &elem.children {
-        number = item.number(styles).unwrap_or(number);
+        number = item.number.get(styles).unwrap_or(number);
 
         let context = Context::new(None, Some(styles));
         let resolved = if full {
@@ -133,8 +134,7 @@ pub fn layout_enum(
 
         // Disable overhang as a workaround to end-aligned dots glitching
         // and decreasing spacing between numbers and items.
-        let resolved =
-            resolved.aligned(number_align).styled(TextElem::set_overhang(false));
+        let resolved = resolved.aligned(number_align).set(TextElem::overhang, false);
 
         // Text in wide enums shall always turn into paragraphs.
         let mut body = item.body.clone();
@@ -146,7 +146,7 @@ pub fn layout_enum(
         cells.push(Cell::new(resolved, locator.next(&())));
         cells.push(Cell::new(Content::empty(), locator.next(&())));
         cells.push(Cell::new(
-            body.styled(EnumElem::set_parents(smallvec![number])),
+            body.set(EnumElem::parents, smallvec![number]),
             locator.next(&item.body.span()),
         ));
         number =

crates/typst-layout/src/math/accent.rs

@@ -24,7 +24,7 @@ pub fn layout_accent(
     // Try to replace the base glyph with its dotless variant.
     let dtls = style_dtls();
     let base_styles =
-        if top_accent && elem.dotless(styles) { styles.chain(&dtls) } else { styles };
+        if top_accent && elem.dotless.get(styles) { styles.chain(&dtls) } else { styles };
 
     let cramped = style_cramped();
     let base = ctx.layout_into_fragment(&elem.base, base_styles.chain(&cramped))?;
@@ -47,7 +47,7 @@ pub fn layout_accent(
 
     // Forcing the accent to be at least as large as the base makes it too wide
     // in many cases.
-    let width = elem.size(styles).relative_to(base.width());
+    let width = elem.size.resolve(styles).relative_to(base.width());
     let short_fall = ACCENT_SHORT_FALL.at(glyph.item.size);
     glyph.stretch_horizontal(ctx, width - short_fall);
     let accent_attach = glyph.accent_attach.0;

crates/typst-layout/src/math/attach.rs

@@ -31,16 +31,16 @@ pub fn layout_attach(
     let mut base = ctx.layout_into_fragment(&elem.base, styles)?;
     let sup_style = style_for_superscript(styles);
     let sup_style_chain = styles.chain(&sup_style);
-    let tl = elem.tl(sup_style_chain);
-    let tr = elem.tr(sup_style_chain);
+    let tl = elem.tl.get_cloned(sup_style_chain);
+    let tr = elem.tr.get_cloned(sup_style_chain);
     let primed = tr.as_ref().is_some_and(|content| content.is::<PrimesElem>());
-    let t = elem.t(sup_style_chain);
+    let t = elem.t.get_cloned(sup_style_chain);
 
     let sub_style = style_for_subscript(styles);
     let sub_style_chain = styles.chain(&sub_style);
-    let bl = elem.bl(sub_style_chain);
-    let br = elem.br(sub_style_chain);
-    let b = elem.b(sub_style_chain);
+    let bl = elem.bl.get_cloned(sub_style_chain);
+    let br = elem.br.get_cloned(sub_style_chain);
+    let b = elem.b.get_cloned(sub_style_chain);
 
     let limits = base.limits().active(styles);
     let (t, tr) = match (t, tr) {
@@ -146,7 +146,7 @@ pub fn layout_limits(
     ctx: &mut MathContext,
     styles: StyleChain,
 ) -> SourceResult<()> {
-    let limits = if elem.inline(styles) { Limits::Always } else { Limits::Display };
+    let limits = if elem.inline.get(styles) { Limits::Always } else { Limits::Display };
     let mut fragment = ctx.layout_into_fragment(&elem.body, styles)?;
     fragment.set_limits(limits);
     ctx.push(fragment);
@@ -161,7 +161,8 @@ fn stretch_size(styles: StyleChain, elem: &Packed<AttachElem>) -> Option<Rel<Abs
         base = &equation.body;
     }
 
-    base.to_packed::<StretchElem>().map(|stretch| stretch.size(styles))
+    base.to_packed::<StretchElem>()
+        .map(|stretch| stretch.size.resolve(styles))
 }
 
 /// Lay out the attachments.
@@ -397,7 +398,7 @@ fn compute_script_shifts(
     base: &MathFragment,
     [tl, tr, bl, br]: [&Option<MathFragment>; 4],
 ) -> (Abs, Abs) {
-    let sup_shift_up = if EquationElem::cramped_in(styles) {
+    let sup_shift_up = if styles.get(EquationElem::cramped) {
         scaled!(ctx, styles, superscript_shift_up_cramped)
     } else {
         scaled!(ctx, styles, superscript_shift_up)

crates/typst-layout/src/math/cancel.rs

@@ -27,16 +27,16 @@ pub fn layout_cancel(
     let mut body = body.into_frame();
     let body_size = body.size();
     let span = elem.span();
-    let length = elem.length(styles);
+    let length = elem.length.resolve(styles);
 
-    let stroke = elem.stroke(styles).unwrap_or(FixedStroke {
-        paint: TextElem::fill_in(styles).as_decoration(),
+    let stroke = elem.stroke.resolve(styles).unwrap_or(FixedStroke {
+        paint: styles.get_ref(TextElem::fill).as_decoration(),
         ..Default::default()
     });
 
-    let invert = elem.inverted(styles);
-    let cross = elem.cross(styles);
-    let angle = elem.angle(styles);
+    let invert = elem.inverted.get(styles);
+    let cross = elem.cross.get(styles);
+    let angle = elem.angle.get_ref(styles);
 
     let invert_first_line = !cross && invert;
     let first_line = draw_cancel_line(
@@ -44,7 +44,7 @@ pub fn layout_cancel(
         length,
         stroke.clone(),
         invert_first_line,
-        &angle,
+        angle,
         body_size,
         styles,
         span,
@@ -57,7 +57,7 @@ pub fn layout_cancel(
     if cross {
         // Draw the second line.
         let second_line =
-            draw_cancel_line(ctx, length, stroke, true, &angle, body_size, styles, span)?;
+            draw_cancel_line(ctx, length, stroke, true, angle, body_size, styles, span)?;
 
         body.push_frame(center, second_line);
     }

crates/typst-layout/src/math/frac.rs

@@ -124,7 +124,7 @@ fn layout_frac_like(
             FrameItem::Shape(
                 Geometry::Line(Point::with_x(line_width)).stroked(
                     FixedStroke::from_pair(
-                        TextElem::fill_in(styles).as_decoration(),
+                        styles.get_ref(TextElem::fill).as_decoration(),
                         thickness,
                     ),
                 ),

crates/typst-layout/src/math/fragment.rs

@@ -315,7 +315,8 @@ impl GlyphFragment {
         let cluster = info.cluster as usize;
         let c = text[cluster..].chars().next().unwrap();
         let limits = Limits::for_char(c);
-        let class = EquationElem::class_in(styles)
+        let class = styles
+            .get(EquationElem::class)
             .or_else(|| default_math_class(c))
             .unwrap_or(MathClass::Normal);
 
@@ -331,11 +332,11 @@ impl GlyphFragment {
 
         let item = TextItem {
             font: font.clone(),
-            size: TextElem::size_in(styles),
-            fill: TextElem::fill_in(styles).as_decoration(),
-            stroke: TextElem::stroke_in(styles).map(|s| s.unwrap_or_default()),
-            lang: TextElem::lang_in(styles),
-            region: TextElem::region_in(styles),
+            size: styles.resolve(TextElem::size),
+            fill: styles.get_ref(TextElem::fill).as_decoration(),
+            stroke: styles.resolve(TextElem::stroke).map(|s| s.unwrap_or_default()),
+            lang: styles.get(TextElem::lang),
+            region: styles.get(TextElem::region),
             text: text.into(),
             glyphs: vec![glyph.clone()],
         };
@@ -344,7 +345,7 @@ impl GlyphFragment {
             item,
             base_glyph: glyph,
             // Math
-            math_size: EquationElem::size_in(styles),
+            math_size: styles.get(EquationElem::size),
             class,
             limits,
             mid_stretched: None,
@@ -356,7 +357,7 @@ impl GlyphFragment {
             baseline: None,
             // Misc
             align: Abs::zero(),
-            shift: TextElem::baseline_in(styles),
+            shift: styles.resolve(TextElem::baseline),
             modifiers: FrameModifiers::get_in(styles),
         };
         fragment.update_glyph();
@@ -541,9 +542,9 @@ impl FrameFragment {
         let accent_attach = frame.width() / 2.0;
         Self {
             frame: frame.modified(&FrameModifiers::get_in(styles)),
-            font_size: TextElem::size_in(styles),
-            class: EquationElem::class_in(styles).unwrap_or(MathClass::Normal),
-            math_size: EquationElem::size_in(styles),
+            font_size: styles.resolve(TextElem::size),
+            class: styles.get(EquationElem::class).unwrap_or(MathClass::Normal),
+            math_size: styles.get(EquationElem::size),
             limits: Limits::Never,
             spaced: false,
             base_ascent,
@@ -864,7 +865,7 @@ impl Limits {
     pub fn active(&self, styles: StyleChain) -> bool {
         match self {
             Self::Always => true,
-            Self::Display => EquationElem::size_in(styles) == MathSize::Display,
+            Self::Display => styles.get(EquationElem::size) == MathSize::Display,
             Self::Never => false,
         }
     }

crates/typst-layout/src/math/lr.rs

@@ -22,7 +22,7 @@ pub fn layout_lr(
 
     // Extract implicit LrElem.
     if let Some(lr) = body.to_packed::<LrElem>() {
-        if lr.size(styles).is_one() {
+        if lr.size.get(styles).is_one() {
             body = &lr.body;
         }
     }
@@ -41,7 +41,7 @@ pub fn layout_lr(
         .unwrap_or_default();
 
     let relative_to = 2.0 * max_extent;
-    let height = elem.size(styles);
+    let height = elem.size.resolve(styles);
 
     // Scale up fragments at both ends.
     match inner_fragments {

crates/typst-layout/src/math/mat.rs

@@ -30,15 +30,15 @@ pub fn layout_vec(
         ctx,
         styles,
         &[column],
-        elem.align(styles),
+        elem.align.resolve(styles),
         LeftRightAlternator::Right,
         None,
-        Axes::with_y(elem.gap(styles)),
+        Axes::with_y(elem.gap.resolve(styles)),
         span,
         "elements",
     )?;
 
-    let delim = elem.delim(styles);
+    let delim = elem.delim.get(styles);
     layout_delimiters(ctx, styles, frame, delim.open(), delim.close(), span)
 }
 
@@ -59,14 +59,17 @@ pub fn layout_cases(
         FixedAlignment::Start,
         LeftRightAlternator::None,
         None,
-        Axes::with_y(elem.gap(styles)),
+        Axes::with_y(elem.gap.resolve(styles)),
         span,
         "branches",
     )?;
 
-    let delim = elem.delim(styles);
-    let (open, close) =
-        if elem.reverse(styles) { (None, delim.close()) } else { (delim.open(), None) };
+    let delim = elem.delim.get(styles);
+    let (open, close) = if elem.reverse.get(styles) {
+        (None, delim.close())
+    } else {
+        (delim.open(), None)
+    };
     layout_delimiters(ctx, styles, frame, open, close, span)
 }
 
@@ -81,7 +84,7 @@ pub fn layout_mat(
     let rows = &elem.rows;
     let ncols = rows.first().map_or(0, |row| row.len());
 
-    let augment = elem.augment(styles);
+    let augment = elem.augment.resolve(styles);
     if let Some(aug) = &augment {
         for &offset in &aug.hline.0 {
             if offset == 0 || offset.unsigned_abs() >= rows.len() {
@@ -116,15 +119,15 @@ pub fn layout_mat(
         ctx,
         styles,
         &columns,
-        elem.align(styles),
+        elem.align.resolve(styles),
         LeftRightAlternator::Right,
         augment,
-        Axes::new(elem.column_gap(styles), elem.row_gap(styles)),
+        Axes::new(elem.column_gap.resolve(styles), elem.row_gap.resolve(styles)),
         span,
         "cells",
     )?;
 
-    let delim = elem.delim(styles);
+    let delim = elem.delim.get(styles);
     layout_delimiters(ctx, styles, frame, delim.open(), delim.close(), span)
 }
 
@@ -157,7 +160,7 @@ fn layout_body(
     let default_stroke_thickness = DEFAULT_STROKE_THICKNESS.resolve(styles);
     let default_stroke = FixedStroke {
         thickness: default_stroke_thickness,
-        paint: TextElem::fill_in(styles).as_decoration(),
+        paint: styles.get_ref(TextElem::fill).as_decoration(),
         cap: LineCap::Square,
         ..Default::default()
     };

crates/typst-layout/src/math/mod.rs

@@ -51,7 +51,7 @@ pub fn layout_equation_inline(
     styles: StyleChain,
     region: Size,
 ) -> SourceResult<Vec<InlineItem>> {
-    assert!(!elem.block(styles));
+    assert!(!elem.block.get(styles));
 
     let font = find_math_font(engine, styles, elem.span())?;
 
@@ -78,12 +78,12 @@ pub fn layout_equation_inline(
     for item in &mut items {
         let InlineItem::Frame(frame) = item else { continue };
 
-        let slack = ParElem::leading_in(styles) * 0.7;
+        let slack = styles.resolve(ParElem::leading) * 0.7;
 
         let (t, b) = font.edges(
-            TextElem::top_edge_in(styles),
-            TextElem::bottom_edge_in(styles),
-            TextElem::size_in(styles),
+            styles.get(TextElem::top_edge),
+            styles.get(TextElem::bottom_edge),
+            styles.resolve(TextElem::size),
             TextEdgeBounds::Frame(frame),
         );
 
@@ -105,7 +105,7 @@ pub fn layout_equation_block(
     styles: StyleChain,
     regions: Regions,
 ) -> SourceResult<Fragment> {
-    assert!(elem.block(styles));
+    assert!(elem.block.get(styles));
 
     let span = elem.span();
     let font = find_math_font(engine, styles, span)?;
@@ -121,7 +121,7 @@ pub fn layout_equation_block(
         .multiline_frame_builder(styles);
     let width = full_equation_builder.size.x;
 
-    let equation_builders = if BlockElem::breakable_in(styles) {
+    let equation_builders = if styles.get(BlockElem::breakable) {
         let mut rows = full_equation_builder.frames.into_iter().peekable();
         let mut equation_builders = vec![];
         let mut last_first_pos = Point::zero();
@@ -188,7 +188,7 @@ pub fn layout_equation_block(
         vec![full_equation_builder]
     };
 
-    let Some(numbering) = (**elem).numbering(styles) else {
+    let Some(numbering) = elem.numbering.get_ref(styles) else {
         let frames = equation_builders
             .into_iter()
             .map(MathRunFrameBuilder::build)
@@ -197,7 +197,7 @@ pub fn layout_equation_block(
     };
 
     let pod = Region::new(regions.base(), Axes::splat(false));
-    let counter = Counter::of(EquationElem::elem())
+    let counter = Counter::of(EquationElem::ELEM)
         .display_at_loc(engine, elem.location().unwrap(), styles, numbering)?
         .spanned(span);
     let number = crate::layout_frame(engine, &counter, locator.next(&()), styles, pod)?;
@@ -205,7 +205,7 @@ pub fn layout_equation_block(
     static NUMBER_GUTTER: Em = Em::new(0.5);
     let full_number_width = number.width() + NUMBER_GUTTER.resolve(styles);
 
-    let number_align = match elem.number_align(styles) {
+    let number_align = match elem.number_align.get(styles) {
         SpecificAlignment::H(h) => SpecificAlignment::Both(h, VAlignment::Horizon),
         SpecificAlignment::V(v) => SpecificAlignment::Both(OuterHAlignment::End, v),
         SpecificAlignment::Both(h, v) => SpecificAlignment::Both(h, v),
@@ -224,7 +224,7 @@ pub fn layout_equation_block(
                 builder,
                 number.clone(),
                 number_align.resolve(styles),
-                AlignElem::alignment_in(styles).resolve(styles).x,
+                styles.get(AlignElem::alignment).resolve(styles).x,
                 regions.size.x,
                 full_number_width,
             )
@@ -472,7 +472,9 @@ impl<'a, 'v, 'e> MathContext<'a, 'v, 'e> {
         let outer = styles;
         for (elem, styles) in pairs {
             // Hack because the font is fixed in math.
-            if styles != outer && TextElem::font_in(styles) != TextElem::font_in(outer) {
+            if styles != outer
+                && styles.get_ref(TextElem::font) != outer.get_ref(TextElem::font)
+            {
                 let frame = layout_external(elem, self, styles)?;
                 self.push(FrameFragment::new(styles, frame).with_spaced(true));
                 continue;
@@ -603,7 +605,10 @@ fn layout_h(
 ) -> SourceResult<()> {
     if let Spacing::Rel(rel) = elem.amount {
         if rel.rel.is_zero() {
-            ctx.push(MathFragment::Spacing(rel.abs.resolve(styles), elem.weak(styles)));
+            ctx.push(MathFragment::Spacing(
+                rel.abs.resolve(styles),
+                elem.weak.get(styles),
+            ));
         }
     }
     Ok(())
@@ -616,7 +621,7 @@ fn layout_class(
     ctx: &mut MathContext,
     styles: StyleChain,
 ) -> SourceResult<()> {
-    let style = EquationElem::set_class(Some(elem.class)).wrap();
+    let style = EquationElem::class.set(Some(elem.class)).wrap();
     let mut fragment = ctx.layout_into_fragment(&elem.body, styles.chain(&style))?;
     fragment.set_class(elem.class);
     fragment.set_limits(Limits::for_class(elem.class));
@@ -642,7 +647,7 @@ fn layout_op(
             .with_italics_correction(italics)
             .with_accent_attach(accent_attach)
             .with_text_like(text_like)
-            .with_limits(if elem.limits(styles) {
+            .with_limits(if elem.limits.get(styles) {
                 Limits::Display
             } else {
                 Limits::Never

crates/typst-layout/src/math/root.rs

@@ -17,7 +17,7 @@ pub fn layout_root(
     ctx: &mut MathContext,
     styles: StyleChain,
 ) -> SourceResult<()> {
-    let index = elem.index(styles);
+    let index = elem.index.get_ref(styles);
     let span = elem.span();
 
     let gap = scaled!(
@@ -54,7 +54,7 @@ pub fn layout_root(
     let sqrt = sqrt.into_frame();
 
     // Layout the index.
-    let sscript = EquationElem::set_size(MathSize::ScriptScript).wrap();
+    let sscript = EquationElem::size.set(MathSize::ScriptScript).wrap();
     let index = index
         .as_ref()
         .map(|elem| ctx.layout_into_frame(elem, styles.chain(&sscript)))
@@ -112,7 +112,7 @@ pub fn layout_root(
         FrameItem::Shape(
             Geometry::Line(Point::with_x(radicand.width())).stroked(
                 FixedStroke::from_pair(
-                    TextElem::fill_in(styles).as_decoration(),
+                    styles.get_ref(TextElem::fill).as_decoration(),
                     thickness,
                 ),
             ),

crates/typst-layout/src/math/run.rs

@@ -194,13 +194,13 @@ impl MathRun {
         let row_count = rows.len();
         let alignments = alignments(&rows);
 
-        let leading = if EquationElem::size_in(styles) >= MathSize::Text {
-            ParElem::leading_in(styles)
+        let leading = if styles.get(EquationElem::size) >= MathSize::Text {
+            styles.resolve(ParElem::leading)
         } else {
             TIGHT_LEADING.resolve(styles)
         };
 
-        let align = AlignElem::alignment_in(styles).resolve(styles).x;
+        let align = styles.resolve(AlignElem::alignment).x;
         let mut frames: Vec<(Frame, Point)> = vec![];
         let mut size = Size::zero();
         for (i, row) in rows.into_iter().enumerate() {

crates/typst-layout/src/math/shared.rs

@@ -10,7 +10,7 @@ use super::{LeftRightAlternator, MathContext, MathFragment, MathRun};
 
 macro_rules! scaled {
     ($ctx:expr, $styles:expr, text: $text:ident, display: $display:ident $(,)?) => {
-        match typst_library::math::EquationElem::size_in($styles) {
+        match $styles.get(typst_library::math::EquationElem::size) {
             typst_library::math::MathSize::Display => scaled!($ctx, $styles, $display),
             _ => scaled!($ctx, $styles, $text),
         }
@@ -19,7 +19,7 @@ macro_rules! scaled {
         $crate::math::Scaled::scaled(
             $ctx.constants.$name(),
             $ctx,
-            typst_library::text::TextElem::size_in($styles),
+            $styles.resolve(typst_library::text::TextElem::size),
         )
     };
 }
@@ -58,55 +58,62 @@ impl Scaled for MathValue<'_> {
 
 /// Styles something as cramped.
 pub fn style_cramped() -> LazyHash<Style> {
-    EquationElem::set_cramped(true).wrap()
+    EquationElem::cramped.set(true).wrap()
 }
 
 /// Sets flac OpenType feature.
 pub fn style_flac() -> LazyHash<Style> {
-    TextElem::set_features(FontFeatures(vec![(Tag::from_bytes(b"flac"), 1)])).wrap()
+    TextElem::features
+        .set(FontFeatures(vec![(Tag::from_bytes(b"flac"), 1)]))
+        .wrap()
 }
 
 /// Sets dtls OpenType feature.
 pub fn style_dtls() -> LazyHash<Style> {
-    TextElem::set_features(FontFeatures(vec![(Tag::from_bytes(b"dtls"), 1)])).wrap()
+    TextElem::features
+        .set(FontFeatures(vec![(Tag::from_bytes(b"dtls"), 1)]))
+        .wrap()
 }
 
 /// The style for subscripts in the current style.
 pub fn style_for_subscript(styles: StyleChain) -> [LazyHash<Style>; 2] {
-    [style_for_superscript(styles), EquationElem::set_cramped(true).wrap()]
+    [style_for_superscript(styles), EquationElem::cramped.set(true).wrap()]
 }
 
 /// The style for superscripts in the current style.
 pub fn style_for_superscript(styles: StyleChain) -> LazyHash<Style> {
-    EquationElem::set_size(match EquationElem::size_in(styles) {
-        MathSize::Display | MathSize::Text => MathSize::Script,
-        MathSize::Script | MathSize::ScriptScript => MathSize::ScriptScript,
-    })
-    .wrap()
+    EquationElem::size
+        .set(match styles.get(EquationElem::size) {
+            MathSize::Display | MathSize::Text => MathSize::Script,
+            MathSize::Script | MathSize::ScriptScript => MathSize::ScriptScript,
+        })
+        .wrap()
 }
 
 /// The style for numerators in the current style.
 pub fn style_for_numerator(styles: StyleChain) -> LazyHash<Style> {
-    EquationElem::set_size(match EquationElem::size_in(styles) {
-        MathSize::Display => MathSize::Text,
-        MathSize::Text => MathSize::Script,
-        MathSize::Script | MathSize::ScriptScript => MathSize::ScriptScript,
-    })
-    .wrap()
+    EquationElem::size
+        .set(match styles.get(EquationElem::size) {
+            MathSize::Display => MathSize::Text,
+            MathSize::Text => MathSize::Script,
+            MathSize::Script | MathSize::ScriptScript => MathSize::ScriptScript,
+        })
+        .wrap()
 }
 
 /// The style for denominators in the current style.
 pub fn style_for_denominator(styles: StyleChain) -> [LazyHash<Style>; 2] {
-    [style_for_numerator(styles), EquationElem::set_cramped(true).wrap()]
+    [style_for_numerator(styles), EquationElem::cramped.set(true).wrap()]
 }
 
 /// Styles to add font constants to the style chain.
 pub fn style_for_script_scale(ctx: &MathContext) -> LazyHash<Style> {
-    EquationElem::set_script_scale((
-        ctx.constants.script_percent_scale_down(),
-        ctx.constants.script_script_percent_scale_down(),
-    ))
-    .wrap()
+    EquationElem::script_scale
+        .set((
+            ctx.constants.script_percent_scale_down(),
+            ctx.constants.script_script_percent_scale_down(),
+        ))
+        .wrap()
 }
 
 /// Stack rows on top of each other.

crates/typst-layout/src/math/stretch.rs

@@ -14,7 +14,14 @@ pub fn layout_stretch(
     styles: StyleChain,
 ) -> SourceResult<()> {
     let mut fragment = ctx.layout_into_fragment(&elem.body, styles)?;
-    stretch_fragment(ctx, &mut fragment, None, None, elem.size(styles), Abs::zero());
+    stretch_fragment(
+        ctx,
+        &mut fragment,
+        None,
+        None,
+        elem.size.resolve(styles),
+        Abs::zero(),
+    );
     ctx.push(fragment);
     Ok(())
 }

crates/typst-layout/src/math/text.rs

@@ -77,8 +77,8 @@ fn layout_inline_text(
         Ok(FrameFragment::new(styles, frame).with_text_like(true))
     } else {
         let local = [
-            TextElem::set_top_edge(TopEdge::Metric(TopEdgeMetric::Bounds)),
-            TextElem::set_bottom_edge(BottomEdge::Metric(BottomEdgeMetric::Bounds)),
+            TextElem::top_edge.set(TopEdge::Metric(TopEdgeMetric::Bounds)),
+            TextElem::bottom_edge.set(BottomEdge::Metric(BottomEdgeMetric::Bounds)),
         ]
         .map(|p| p.wrap());
 
@@ -150,7 +150,7 @@ fn adjust_glyph_layout(
     styles: StyleChain,
 ) {
     if glyph.class == MathClass::Large {
-        if EquationElem::size_in(styles) == MathSize::Display {
+        if styles.get(EquationElem::size) == MathSize::Display {
             let height = scaled!(ctx, styles, display_operator_min_height)
                 .max(SQRT_2 * glyph.size.y);
             glyph.stretch_vertical(ctx, height);
@@ -169,9 +169,9 @@ fn adjust_glyph_layout(
 fn styled_char(styles: StyleChain, c: char, auto_italic: bool) -> char {
     use MathVariant::*;
 
-    let variant = EquationElem::variant_in(styles);
-    let bold = EquationElem::bold_in(styles);
-    let italic = EquationElem::italic_in(styles).unwrap_or(
+    let variant = styles.get(EquationElem::variant);
+    let bold = styles.get(EquationElem::bold);
+    let italic = styles.get(EquationElem::italic).unwrap_or(
         auto_italic
             && matches!(
                 c,

crates/typst-layout/src/math/underover.rs

@@ -56,7 +56,7 @@ pub fn layout_underbrace(
         ctx,
         styles,
         &elem.body,
-        &elem.annotation(styles),
+        elem.annotation.get_ref(styles),
         '⏟',
         BRACE_GAP,
         Position::Under,
@@ -75,7 +75,7 @@ pub fn layout_overbrace(
         ctx,
         styles,
         &elem.body,
-        &elem.annotation(styles),
+        elem.annotation.get_ref(styles),
         '⏞',
         BRACE_GAP,
         Position::Over,
@@ -94,7 +94,7 @@ pub fn layout_underbracket(
         ctx,
         styles,
         &elem.body,
-        &elem.annotation(styles),
+        elem.annotation.get_ref(styles),
         '⎵',
         BRACKET_GAP,
         Position::Under,
@@ -113,7 +113,7 @@ pub fn layout_overbracket(
         ctx,
         styles,
         &elem.body,
-        &elem.annotation(styles),
+        elem.annotation.get_ref(styles),
         '⎴',
         BRACKET_GAP,
         Position::Over,
@@ -132,7 +132,7 @@ pub fn layout_underparen(
         ctx,
         styles,
         &elem.body,
-        &elem.annotation(styles),
+        elem.annotation.get_ref(styles),
         '⏝',
         PAREN_GAP,
         Position::Under,
@@ -151,7 +151,7 @@ pub fn layout_overparen(
         ctx,
         styles,
         &elem.body,
-        &elem.annotation(styles),
+        elem.annotation.get_ref(styles),
         '⏜',
         PAREN_GAP,
         Position::Over,
@@ -170,7 +170,7 @@ pub fn layout_undershell(
         ctx,
         styles,
         &elem.body,
-        &elem.annotation(styles),
+        elem.annotation.get_ref(styles),
         '⏡',
         SHELL_GAP,
         Position::Under,
@@ -189,7 +189,7 @@ pub fn layout_overshell(
         ctx,
         styles,
         &elem.body,
-        &elem.annotation(styles),
+        elem.annotation.get_ref(styles),
         '⏠',
         SHELL_GAP,
         Position::Over,
@@ -251,7 +251,7 @@ fn layout_underoverline(
         line_pos,
         FrameItem::Shape(
             Geometry::Line(Point::with_x(line_width)).stroked(FixedStroke {
-                paint: TextElem::fill_in(styles).as_decoration(),
+                paint: styles.get_ref(TextElem::fill).as_decoration(),
                 thickness: bar_height,
                 ..FixedStroke::default()
             }),

crates/typst-layout/src/modifiers.rs

@@ -29,8 +29,8 @@ impl FrameModifiers {
     /// Retrieve all modifications that should be applied per-frame.
     pub fn get_in(styles: StyleChain) -> Self {
         Self {
-            dest: LinkElem::current_in(styles),
-            hidden: HideElem::hidden_in(styles),
+            dest: styles.get_cloned(LinkElem::current),
+            hidden: styles.get(HideElem::hidden),
         }
     }
 }
@@ -83,7 +83,7 @@ pub trait FrameModifyText {
 impl FrameModifyText for Frame {
     fn modify_text(&mut self, styles: StyleChain) {
         let modifiers = FrameModifiers::get_in(styles);
-        let expand_y = 0.5 * ParElem::leading_in(styles);
+        let expand_y = 0.5 * styles.resolve(ParElem::leading);
         let outset = Sides::new(Abs::zero(), expand_y, Abs::zero(), expand_y);
         modify_frame(self, &modifiers, Some(outset));
     }
@@ -130,7 +130,7 @@ where
     let outer = styles;
     let mut styles = styles;
     if modifiers.dest.is_some() {
-        reset = LinkElem::set_current(None).wrap();
+        reset = LinkElem::current.set(None).wrap();
         styles = outer.chain(&reset);
     }
 

crates/typst-layout/src/pad.rs

@@ -1,6 +1,6 @@
 use typst_library::diag::SourceResult;
 use typst_library::engine::Engine;
-use typst_library::foundations::{Packed, Resolve, StyleChain};
+use typst_library::foundations::{Packed, StyleChain};
 use typst_library::introspection::Locator;
 use typst_library::layout::{
     Abs, Fragment, Frame, PadElem, Point, Regions, Rel, Sides, Size,
@@ -16,10 +16,10 @@ pub fn layout_pad(
     regions: Regions,
 ) -> SourceResult<Fragment> {
     let padding = Sides::new(
-        elem.left(styles).resolve(styles),
-        elem.top(styles).resolve(styles),
-        elem.right(styles).resolve(styles),
-        elem.bottom(styles).resolve(styles),
+        elem.left.resolve(styles),
+        elem.top.resolve(styles),
+        elem.right.resolve(styles),
+        elem.bottom.resolve(styles),
     );
 
     let mut backlog = vec![];

crates/typst-layout/src/pages/collect.rs

@@ -39,14 +39,14 @@ pub fn collect<'a>(
         if let Some(pagebreak) = elem.to_packed::<PagebreakElem>() {
             // Add a blank page if we encounter a strong pagebreak and there was
             // a staged empty page.
-            let strong = !pagebreak.weak(styles);
+            let strong = !pagebreak.weak.get(styles);
             if strong && staged_empty_page {
                 let locator = locator.next(&elem.span());
                 items.push(Item::Run(&[], initial, locator));
             }
 
             // Add an instruction to adjust the page parity if requested.
-            if let Some(parity) = pagebreak.to(styles) {
+            if let Some(parity) = pagebreak.to.get(styles) {
                 let locator = locator.next(&elem.span());
                 items.push(Item::Parity(parity, styles, locator));
             }
@@ -56,7 +56,7 @@ pub fn collect<'a>(
             // the scope of a page set rule to ensure a page boundary. Its
             // styles correspond to the styles _before_ the page set rule, so we
             // don't want to apply it to a potential empty page.
-            if !pagebreak.boundary(styles) {
+            if !pagebreak.boundary.get(styles) {
                 initial = styles;
             }
 
@@ -94,7 +94,7 @@ pub fn collect<'a>(
             if group.iter().all(|(c, _)| c.is::<TagElem>())
                 && !(staged_empty_page
                     && children.iter().all(|&(c, s)| {
-                        c.to_packed::<PagebreakElem>().is_some_and(|c| c.boundary(s))
+                        c.to_packed::<PagebreakElem>().is_some_and(|c| c.boundary.get(s))
                     }))
             {
                 items.push(Item::Tags(group));

crates/typst-layout/src/pages/run.rs

@@ -101,10 +101,10 @@ fn layout_page_run_impl(
 
     // When one of the lengths is infinite the page fits its content along
     // that axis.
-    let width = PageElem::width_in(styles).unwrap_or(Abs::inf());
-    let height = PageElem::height_in(styles).unwrap_or(Abs::inf());
+    let width = styles.resolve(PageElem::width).unwrap_or(Abs::inf());
+    let height = styles.resolve(PageElem::height).unwrap_or(Abs::inf());
     let mut size = Size::new(width, height);
-    if PageElem::flipped_in(styles) {
+    if styles.get(PageElem::flipped) {
         std::mem::swap(&mut size.x, &mut size.y);
     }
 
@@ -115,7 +115,7 @@ fn layout_page_run_impl(
 
     // Determine the margins.
     let default = Rel::<Length>::from((2.5 / 21.0) * min);
-    let margin = PageElem::margin_in(styles);
+    let margin = styles.get(PageElem::margin);
     let two_sided = margin.two_sided.unwrap_or(false);
     let margin = margin
         .sides
@@ -123,22 +123,24 @@ fn layout_page_run_impl(
         .resolve(styles)
         .relative_to(size);
 
-    let fill = PageElem::fill_in(styles);
-    let foreground = PageElem::foreground_in(styles);
-    let background = PageElem::background_in(styles);
-    let header_ascent = PageElem::header_ascent_in(styles).relative_to(margin.top);
-    let footer_descent = PageElem::footer_descent_in(styles).relative_to(margin.bottom);
-    let numbering = PageElem::numbering_in(styles);
-    let supplement = match PageElem::supplement_in(styles) {
+    let fill = styles.get_cloned(PageElem::fill);
+    let foreground = styles.get_ref(PageElem::foreground);
+    let background = styles.get_ref(PageElem::background);
+    let header_ascent = styles.resolve(PageElem::header_ascent).relative_to(margin.top);
+    let footer_descent =
+        styles.resolve(PageElem::footer_descent).relative_to(margin.bottom);
+    let numbering = styles.get_ref(PageElem::numbering);
+    let supplement = match styles.get_cloned(PageElem::supplement) {
         Smart::Auto => TextElem::packed(PageElem::local_name_in(styles)),
         Smart::Custom(content) => content.unwrap_or_default(),
     };
-    let number_align = PageElem::number_align_in(styles);
-    let binding =
-        PageElem::binding_in(styles).unwrap_or_else(|| match TextElem::dir_in(styles) {
+    let number_align = styles.get(PageElem::number_align);
+    let binding = styles.get(PageElem::binding).unwrap_or_else(|| {
+        match styles.resolve(TextElem::dir) {
             Dir::LTR => Binding::Left,
             _ => Binding::Right,
-        });
+        }
+    });
 
     // Construct the numbering (for header or footer).
     let numbering_marginal = numbering.as_ref().map(|numbering| {
@@ -163,8 +165,8 @@ fn layout_page_run_impl(
         counter
     });
 
-    let header = PageElem::header_in(styles);
-    let footer = PageElem::footer_in(styles);
+    let header = styles.get_ref(PageElem::header);
+    let footer = styles.get_ref(PageElem::footer);
     let (header, footer) = if matches!(number_align.y(), Some(OuterVAlignment::Top)) {
         (header.as_ref().unwrap_or(&numbering_marginal), footer.as_ref().unwrap_or(&None))
     } else {
@@ -179,15 +181,15 @@ fn layout_page_run_impl(
         &mut locator,
         styles,
         Regions::repeat(area, area.map(Abs::is_finite)),
-        PageElem::columns_in(styles),
-        ColumnsElem::gutter_in(styles),
+        styles.get(PageElem::columns),
+        styles.get(ColumnsElem::gutter).resolve(styles),
         FlowMode::Root,
     )?;
 
     // Layouts a single marginal.
     let mut layout_marginal = |content: &Option<Content>, area, align| {
         let Some(content) = content else { return Ok(None) };
-        let aligned = content.clone().styled(AlignElem::set_alignment(align));
+        let aligned = content.clone().set(AlignElem::alignment, align);
         crate::layout_frame(
             &mut engine,
             &aligned,

crates/typst-layout/src/repeat.rs

@@ -29,7 +29,7 @@ pub fn layout_repeat(
         frame.set_baseline(piece.baseline());
     }
 
-    let mut gap = elem.gap(styles).resolve(styles);
+    let mut gap = elem.gap.resolve(styles);
     let fill = region.size.x;
     let width = piece.width();
 
@@ -47,12 +47,12 @@ pub fn layout_repeat(
     let count = ((fill + gap) / (width + gap)).floor();
     let remaining = (fill + gap) % (width + gap);
 
-    let justify = elem.justify(styles);
+    let justify = elem.justify.get(styles);
     if justify {
         gap += remaining / (count - 1.0);
     }
 
-    let align = AlignElem::alignment_in(styles).resolve(styles);
+    let align = styles.get(AlignElem::alignment).resolve(styles);
     let mut offset = Abs::zero();
     if count == 1.0 || !justify {
         offset += align.x.position(remaining);

crates/typst-layout/src/rules.rs

@@ -0,0 +1,890 @@
+use std::num::NonZeroUsize;
+
+use comemo::Track;
+use ecow::{eco_format, EcoVec};
+use smallvec::smallvec;
+use typst_library::diag::{bail, At, SourceResult};
+use typst_library::foundations::{
+    dict, Content, Context, NativeElement, NativeRuleMap, Packed, Resolve, ShowFn, Smart,
+    StyleChain, Target,
+};
+use typst_library::introspection::{Counter, Locator, LocatorLink};
+use typst_library::layout::{
+    Abs, AlignElem, Alignment, Axes, BlockBody, BlockElem, ColumnsElem, Em, GridCell,
+    GridChild, GridElem, GridItem, HAlignment, HElem, HideElem, InlineElem, LayoutElem,
+    Length, MoveElem, OuterVAlignment, PadElem, PlaceElem, PlacementScope, Region, Rel,
+    RepeatElem, RotateElem, ScaleElem, Sides, Size, Sizing, SkewElem, Spacing,
+    StackChild, StackElem, TrackSizings, VElem,
+};
+use typst_library::math::EquationElem;
+use typst_library::model::{
+    Attribution, BibliographyElem, CiteElem, CiteGroup, CslSource, Destination, EmphElem,
+    EnumElem, FigureCaption, FigureElem, FootnoteElem, FootnoteEntry, HeadingElem,
+    LinkElem, LinkTarget, ListElem, Outlinable, OutlineElem, OutlineEntry, ParElem,
+    ParbreakElem, QuoteElem, RefElem, StrongElem, TableCell, TableElem, TermsElem, Works,
+};
+use typst_library::pdf::EmbedElem;
+use typst_library::text::{
+    DecoLine, Decoration, HighlightElem, ItalicToggle, LinebreakElem, LocalName,
+    OverlineElem, RawElem, RawLine, ScriptKind, ShiftSettings, Smallcaps, SmallcapsElem,
+    SpaceElem, StrikeElem, SubElem, SuperElem, TextElem, TextSize, UnderlineElem,
+    WeightDelta,
+};
+use typst_library::visualize::{
+    CircleElem, CurveElem, EllipseElem, ImageElem, LineElem, PathElem, PolygonElem,
+    RectElem, SquareElem, Stroke,
+};
+use typst_utils::{Get, NonZeroExt, Numeric};
+
+/// Register show rules for the [paged target](Target::Paged).
+pub fn register(rules: &mut NativeRuleMap) {
+    use Target::Paged;
+
+    // Model.
+    rules.register(Paged, STRONG_RULE);
+    rules.register(Paged, EMPH_RULE);
+    rules.register(Paged, LIST_RULE);
+    rules.register(Paged, ENUM_RULE);
+    rules.register(Paged, TERMS_RULE);
+    rules.register(Paged, LINK_RULE);
+    rules.register(Paged, HEADING_RULE);
+    rules.register(Paged, FIGURE_RULE);
+    rules.register(Paged, FIGURE_CAPTION_RULE);
+    rules.register(Paged, QUOTE_RULE);
+    rules.register(Paged, FOOTNOTE_RULE);
+    rules.register(Paged, FOOTNOTE_ENTRY_RULE);
+    rules.register(Paged, OUTLINE_RULE);
+    rules.register(Paged, OUTLINE_ENTRY_RULE);
+    rules.register(Paged, REF_RULE);
+    rules.register(Paged, CITE_GROUP_RULE);
+    rules.register(Paged, BIBLIOGRAPHY_RULE);
+    rules.register(Paged, TABLE_RULE);
+    rules.register(Paged, TABLE_CELL_RULE);
+
+    // Text.
+    rules.register(Paged, SUB_RULE);
+    rules.register(Paged, SUPER_RULE);
+    rules.register(Paged, UNDERLINE_RULE);
+    rules.register(Paged, OVERLINE_RULE);
+    rules.register(Paged, STRIKE_RULE);
+    rules.register(Paged, HIGHLIGHT_RULE);
+    rules.register(Paged, SMALLCAPS_RULE);
+    rules.register(Paged, RAW_RULE);
+    rules.register(Paged, RAW_LINE_RULE);
+
+    // Layout.
+    rules.register(Paged, ALIGN_RULE);
+    rules.register(Paged, PAD_RULE);
+    rules.register(Paged, COLUMNS_RULE);
+    rules.register(Paged, STACK_RULE);
+    rules.register(Paged, GRID_RULE);
+    rules.register(Paged, GRID_CELL_RULE);
+    rules.register(Paged, MOVE_RULE);
+    rules.register(Paged, SCALE_RULE);
+    rules.register(Paged, ROTATE_RULE);
+    rules.register(Paged, SKEW_RULE);
+    rules.register(Paged, REPEAT_RULE);
+    rules.register(Paged, HIDE_RULE);
+    rules.register(Paged, LAYOUT_RULE);
+
+    // Visualize.
+    rules.register(Paged, IMAGE_RULE);
+    rules.register(Paged, LINE_RULE);
+    rules.register(Paged, RECT_RULE);
+    rules.register(Paged, SQUARE_RULE);
+    rules.register(Paged, ELLIPSE_RULE);
+    rules.register(Paged, CIRCLE_RULE);
+    rules.register(Paged, POLYGON_RULE);
+    rules.register(Paged, CURVE_RULE);
+    rules.register(Paged, PATH_RULE);
+
+    // Math.
+    rules.register(Paged, EQUATION_RULE);
+
+    // PDF.
+    rules.register(Paged, EMBED_RULE);
+}
+
+const STRONG_RULE: ShowFn<StrongElem> = |elem, _, styles| {
+    Ok(elem
+        .body
+        .clone()
+        .set(TextElem::delta, WeightDelta(elem.delta.get(styles))))
+};
+
+const EMPH_RULE: ShowFn<EmphElem> =
+    |elem, _, _| Ok(elem.body.clone().set(TextElem::emph, ItalicToggle(true)));
+
+const LIST_RULE: ShowFn<ListElem> = |elem, _, styles| {
+    let tight = elem.tight.get(styles);
+
+    let mut realized = BlockElem::multi_layouter(elem.clone(), crate::lists::layout_list)
+        .pack()
+        .spanned(elem.span());
+
+    if tight {
+        let spacing = elem
+            .spacing
+            .get(styles)
+            .unwrap_or_else(|| styles.get(ParElem::leading));
+        let v = VElem::new(spacing.into()).with_weak(true).with_attach(true).pack();
+        realized = v + realized;
+    }
+
+    Ok(realized)
+};
+
+const ENUM_RULE: ShowFn<EnumElem> = |elem, _, styles| {
+    let tight = elem.tight.get(styles);
+
+    let mut realized = BlockElem::multi_layouter(elem.clone(), crate::lists::layout_enum)
+        .pack()
+        .spanned(elem.span());
+
+    if tight {
+        let spacing = elem
+            .spacing
+            .get(styles)
+            .unwrap_or_else(|| styles.get(ParElem::leading));
+        let v = VElem::new(spacing.into()).with_weak(true).with_attach(true).pack();
+        realized = v + realized;
+    }
+
+    Ok(realized)
+};
+
+const TERMS_RULE: ShowFn<TermsElem> = |elem, _, styles| {
+    let span = elem.span();
+    let tight = elem.tight.get(styles);
+
+    let separator = elem.separator.get_ref(styles);
+    let indent = elem.indent.get(styles);
+    let hanging_indent = elem.hanging_indent.get(styles);
+    let gutter = elem.spacing.get(styles).unwrap_or_else(|| {
+        if tight {
+            styles.get(ParElem::leading)
+        } else {
+            styles.get(ParElem::spacing)
+        }
+    });
+
+    let pad = hanging_indent + indent;
+    let unpad = (!hanging_indent.is_zero())
+        .then(|| HElem::new((-hanging_indent).into()).pack().spanned(span));
+
+    let mut children = vec![];
+    for child in elem.children.iter() {
+        let mut seq = vec![];
+        seq.extend(unpad.clone());
+        seq.push(child.term.clone().strong());
+        seq.push(separator.clone());
+        seq.push(child.description.clone());
+
+        // Text in wide term lists shall always turn into paragraphs.
+        if !tight {
+            seq.push(ParbreakElem::shared().clone());
+        }
+
+        children.push(StackChild::Block(Content::sequence(seq)));
+    }
+
+    let padding =
+        Sides::default().with(styles.resolve(TextElem::dir).start(), pad.into());
+
+    let mut realized = StackElem::new(children)
+        .with_spacing(Some(gutter.into()))
+        .pack()
+        .spanned(span)
+        .padded(padding)
+        .set(TermsElem::within, true);
+
+    if tight {
+        let spacing = elem
+            .spacing
+            .get(styles)
+            .unwrap_or_else(|| styles.get(ParElem::leading));
+        let v = VElem::new(spacing.into())
+            .with_weak(true)
+            .with_attach(true)
+            .pack()
+            .spanned(span);
+        realized = v + realized;
+    }
+
+    Ok(realized)
+};
+
+const LINK_RULE: ShowFn<LinkElem> = |elem, engine, _| {
+    let body = elem.body.clone();
+    Ok(match &elem.dest {
+        LinkTarget::Dest(dest) => body.linked(dest.clone()),
+        LinkTarget::Label(label) => {
+            let elem = engine.introspector.query_label(*label).at(elem.span())?;
+            let dest = Destination::Location(elem.location().unwrap());
+            body.linked(dest)
+        }
+    })
+};
+
+const HEADING_RULE: ShowFn<HeadingElem> = |elem, engine, styles| {
+    const SPACING_TO_NUMBERING: Em = Em::new(0.3);
+
+    let span = elem.span();
+    let mut realized = elem.body.clone();
+
+    let hanging_indent = elem.hanging_indent.get(styles);
+    let mut indent = match hanging_indent {
+        Smart::Custom(length) => length.resolve(styles),
+        Smart::Auto => Abs::zero(),
+    };
+
+    if let Some(numbering) = elem.numbering.get_ref(styles).as_ref() {
+        let location = elem.location().unwrap();
+        let numbering = Counter::of(HeadingElem::ELEM)
+            .display_at_loc(engine, location, styles, numbering)?
+            .spanned(span);
+
+        if hanging_indent.is_auto() {
+            let pod = Region::new(Axes::splat(Abs::inf()), Axes::splat(false));
+
+            // We don't have a locator for the numbering here, so we just
+            // use the measurement infrastructure for now.
+            let link = LocatorLink::measure(location);
+            let size = (engine.routines.layout_frame)(
+                engine,
+                &numbering,
+                Locator::link(&link),
+                styles,
+                pod,
+            )?
+            .size();
+
+            indent = size.x + SPACING_TO_NUMBERING.resolve(styles);
+        }
+
+        let spacing = HElem::new(SPACING_TO_NUMBERING.into()).with_weak(true).pack();
+
+        realized = numbering + spacing + realized;
+    }
+
+    let block = if indent != Abs::zero() {
+        let body = HElem::new((-indent).into()).pack() + realized;
+        let inset = Sides::default()
+            .with(styles.resolve(TextElem::dir).start(), Some(indent.into()));
+        BlockElem::new()
+            .with_body(Some(BlockBody::Content(body)))
+            .with_inset(inset)
+    } else {
+        BlockElem::new().with_body(Some(BlockBody::Content(realized)))
+    };
+
+    Ok(block.pack().spanned(span))
+};
+
+const FIGURE_RULE: ShowFn<FigureElem> = |elem, _, styles| {
+    let span = elem.span();
+    let mut realized = elem.body.clone();
+
+    // Build the caption, if any.
+    if let Some(caption) = elem.caption.get_cloned(styles) {
+        let (first, second) = match caption.position.get(styles) {
+            OuterVAlignment::Top => (caption.pack(), realized),
+            OuterVAlignment::Bottom => (realized, caption.pack()),
+        };
+        realized = Content::sequence(vec![
+            first,
+            VElem::new(elem.gap.get(styles).into())
+                .with_weak(true)
+                .pack()
+                .spanned(span),
+            second,
+        ]);
+    }
+
+    // Ensure that the body is considered a paragraph.
+    realized += ParbreakElem::shared().clone().spanned(span);
+
+    // Wrap the contents in a block.
+    realized = BlockElem::new()
+        .with_body(Some(BlockBody::Content(realized)))
+        .pack()
+        .spanned(span);
+
+    // Wrap in a float.
+    if let Some(align) = elem.placement.get(styles) {
+        realized = PlaceElem::new(realized)
+            .with_alignment(align.map(|align| HAlignment::Center + align))
+            .with_scope(elem.scope.get(styles))
+            .with_float(true)
+            .pack()
+            .spanned(span);
+    } else if elem.scope.get(styles) == PlacementScope::Parent {
+        bail!(
+            span,
+            "parent-scoped placement is only available for floating figures";
+            hint: "you can enable floating placement with `figure(placement: auto, ..)`"
+        );
+    }
+
+    Ok(realized)
+};
+
+const FIGURE_CAPTION_RULE: ShowFn<FigureCaption> = |elem, engine, styles| {
+    Ok(BlockElem::new()
+        .with_body(Some(BlockBody::Content(elem.realize(engine, styles)?)))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const QUOTE_RULE: ShowFn<QuoteElem> = |elem, _, styles| {
+    let span = elem.span();
+    let block = elem.block.get(styles);
+
+    let mut realized = elem.body.clone();
+
+    if elem.quotes.get(styles).unwrap_or(!block) {
+        // Add zero-width weak spacing to make the quotes "sticky".
+        let hole = HElem::hole().pack();
+        let sticky = Content::sequence([hole.clone(), realized, hole]);
+        realized = QuoteElem::quoted(sticky, styles);
+    }
+
+    let attribution = elem.attribution.get_ref(styles);
+
+    if block {
+        realized = BlockElem::new()
+            .with_body(Some(BlockBody::Content(realized)))
+            .pack()
+            .spanned(span);
+
+        if let Some(attribution) = attribution.as_ref() {
+            // Bring the attribution a bit closer to the quote.
+            let gap = Spacing::Rel(Em::new(0.9).into());
+            let v = VElem::new(gap).with_weak(true).pack();
+            realized += v;
+            realized += BlockElem::new()
+                .with_body(Some(BlockBody::Content(attribution.realize(span))))
+                .pack()
+                .aligned(Alignment::END);
+        }
+
+        realized = PadElem::new(realized).pack();
+    } else if let Some(Attribution::Label(label)) = attribution {
+        realized += SpaceElem::shared().clone();
+        realized += CiteElem::new(*label).pack().spanned(span);
+    }
+
+    Ok(realized)
+};
+
+const FOOTNOTE_RULE: ShowFn<FootnoteElem> = |elem, engine, styles| {
+    let span = elem.span();
+    let loc = elem.declaration_location(engine).at(span)?;
+    let numbering = elem.numbering.get_ref(styles);
+    let counter = Counter::of(FootnoteElem::ELEM);
+    let num = counter.display_at_loc(engine, loc, styles, numbering)?;
+    let sup = SuperElem::new(num).pack().spanned(span);
+    let loc = loc.variant(1);
+    // Add zero-width weak spacing to make the footnote "sticky".
+    Ok(HElem::hole().pack() + sup.linked(Destination::Location(loc)))
+};
+
+const FOOTNOTE_ENTRY_RULE: ShowFn<FootnoteEntry> = |elem, engine, styles| {
+    let span = elem.span();
+    let number_gap = Em::new(0.05);
+    let default = StyleChain::default();
+    let numbering = elem.note.numbering.get_ref(default);
+    let counter = Counter::of(FootnoteElem::ELEM);
+    let Some(loc) = elem.note.location() else {
+        bail!(
+            span, "footnote entry must have a location";
+            hint: "try using a query or a show rule to customize the footnote instead"
+        );
+    };
+
+    let num = counter.display_at_loc(engine, loc, styles, numbering)?;
+    let sup = SuperElem::new(num)
+        .pack()
+        .spanned(span)
+        .linked(Destination::Location(loc))
+        .located(loc.variant(1));
+
+    Ok(Content::sequence([
+        HElem::new(elem.indent.get(styles).into()).pack(),
+        sup,
+        HElem::new(number_gap.into()).with_weak(true).pack(),
+        elem.note.body_content().unwrap().clone(),
+    ]))
+};
+
+const OUTLINE_RULE: ShowFn<OutlineElem> = |elem, engine, styles| {
+    let span = elem.span();
+
+    // Build the outline title.
+    let mut seq = vec![];
+    if let Some(title) = elem.title.get_cloned(styles).unwrap_or_else(|| {
+        Some(TextElem::packed(Packed::<OutlineElem>::local_name_in(styles)).spanned(span))
+    }) {
+        seq.push(
+            HeadingElem::new(title)
+                .with_depth(NonZeroUsize::ONE)
+                .pack()
+                .spanned(span),
+        );
+    }
+
+    let elems = engine.introspector.query(&elem.target.get_ref(styles).0);
+    let depth = elem.depth.get(styles).unwrap_or(NonZeroUsize::MAX);
+
+    // Build the outline entries.
+    for elem in elems {
+        let Some(outlinable) = elem.with::<dyn Outlinable>() else {
+            bail!(span, "cannot outline {}", elem.func().name());
+        };
+
+        let level = outlinable.level();
+        if outlinable.outlined() && level <= depth {
+            let entry = OutlineEntry::new(level, elem);
+            seq.push(entry.pack().spanned(span));
+        }
+    }
+
+    Ok(Content::sequence(seq))
+};
+
+const OUTLINE_ENTRY_RULE: ShowFn<OutlineEntry> = |elem, engine, styles| {
+    let span = elem.span();
+    let context = Context::new(None, Some(styles));
+    let context = context.track();
+
+    let prefix = elem.prefix(engine, context, span)?;
+    let inner = elem.inner(engine, context, span)?;
+    let block = if elem.element.is::<EquationElem>() {
+        let body = prefix.unwrap_or_default() + inner;
+        BlockElem::new()
+            .with_body(Some(BlockBody::Content(body)))
+            .pack()
+            .spanned(span)
+    } else {
+        elem.indented(engine, context, span, prefix, inner, Em::new(0.5).into())?
+    };
+
+    let loc = elem.element_location().at(span)?;
+    Ok(block.linked(Destination::Location(loc)))
+};
+
+const REF_RULE: ShowFn<RefElem> = |elem, engine, styles| elem.realize(engine, styles);
+
+const CITE_GROUP_RULE: ShowFn<CiteGroup> = |elem, engine, _| elem.realize(engine);
+
+const BIBLIOGRAPHY_RULE: ShowFn<BibliographyElem> = |elem, engine, styles| {
+    const COLUMN_GUTTER: Em = Em::new(0.65);
+    const INDENT: Em = Em::new(1.5);
+
+    let span = elem.span();
+
+    let mut seq = vec![];
+    if let Some(title) = elem.title.get_ref(styles).clone().unwrap_or_else(|| {
+        Some(
+            TextElem::packed(Packed::<BibliographyElem>::local_name_in(styles))
+                .spanned(span),
+        )
+    }) {
+        seq.push(
+            HeadingElem::new(title)
+                .with_depth(NonZeroUsize::ONE)
+                .pack()
+                .spanned(span),
+        );
+    }
+
+    let works = Works::generate(engine).at(span)?;
+    let references = works
+        .references
+        .as_ref()
+        .ok_or_else(|| match elem.style.get_ref(styles).source {
+            CslSource::Named(style) => eco_format!(
+                "CSL style \"{}\" is not suitable for bibliographies",
+                style.display_name()
+            ),
+            CslSource::Normal(..) => {
+                "CSL style is not suitable for bibliographies".into()
+            }
+        })
+        .at(span)?;
+
+    if references.iter().any(|(prefix, _)| prefix.is_some()) {
+        let row_gutter = styles.get(ParElem::spacing);
+
+        let mut cells = vec![];
+        for (prefix, reference) in references {
+            cells.push(GridChild::Item(GridItem::Cell(
+                Packed::new(GridCell::new(prefix.clone().unwrap_or_default()))
+                    .spanned(span),
+            )));
+            cells.push(GridChild::Item(GridItem::Cell(
+                Packed::new(GridCell::new(reference.clone())).spanned(span),
+            )));
+        }
+        seq.push(
+            GridElem::new(cells)
+                .with_columns(TrackSizings(smallvec![Sizing::Auto; 2]))
+                .with_column_gutter(TrackSizings(smallvec![COLUMN_GUTTER.into()]))
+                .with_row_gutter(TrackSizings(smallvec![row_gutter.into()]))
+                .pack()
+                .spanned(span),
+        );
+    } else {
+        for (_, reference) in references {
+            let realized = reference.clone();
+            let block = if works.hanging_indent {
+                let body = HElem::new((-INDENT).into()).pack() + realized;
+                let inset = Sides::default()
+                    .with(styles.resolve(TextElem::dir).start(), Some(INDENT.into()));
+                BlockElem::new()
+                    .with_body(Some(BlockBody::Content(body)))
+                    .with_inset(inset)
+            } else {
+                BlockElem::new().with_body(Some(BlockBody::Content(realized)))
+            };
+
+            seq.push(block.pack().spanned(span));
+        }
+    }
+
+    Ok(Content::sequence(seq))
+};
+
+const TABLE_RULE: ShowFn<TableElem> = |elem, _, _| {
+    Ok(BlockElem::multi_layouter(elem.clone(), crate::grid::layout_table)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const TABLE_CELL_RULE: ShowFn<TableCell> = |elem, _, styles| {
+    show_cell(elem.body.clone(), elem.inset.get(styles), elem.align.get(styles))
+};
+
+const SUB_RULE: ShowFn<SubElem> = |elem, _, styles| {
+    show_script(
+        styles,
+        elem.body.clone(),
+        elem.typographic.get(styles),
+        elem.baseline.get(styles),
+        elem.size.get(styles),
+        ScriptKind::Sub,
+    )
+};
+
+const SUPER_RULE: ShowFn<SuperElem> = |elem, _, styles| {
+    show_script(
+        styles,
+        elem.body.clone(),
+        elem.typographic.get(styles),
+        elem.baseline.get(styles),
+        elem.size.get(styles),
+        ScriptKind::Super,
+    )
+};
+
+fn show_script(
+    styles: StyleChain,
+    body: Content,
+    typographic: bool,
+    baseline: Smart<Length>,
+    size: Smart<TextSize>,
+    kind: ScriptKind,
+) -> SourceResult<Content> {
+    let font_size = styles.resolve(TextElem::size);
+    Ok(body.set(
+        TextElem::shift_settings,
+        Some(ShiftSettings {
+            typographic,
+            shift: baseline.map(|l| -Em::from_length(l, font_size)),
+            size: size.map(|t| Em::from_length(t.0, font_size)),
+            kind,
+        }),
+    ))
+}
+
+const UNDERLINE_RULE: ShowFn<UnderlineElem> = |elem, _, styles| {
+    Ok(elem.body.clone().set(
+        TextElem::deco,
+        smallvec![Decoration {
+            line: DecoLine::Underline {
+                stroke: elem.stroke.resolve(styles).unwrap_or_default(),
+                offset: elem.offset.resolve(styles),
+                evade: elem.evade.get(styles),
+                background: elem.background.get(styles),
+            },
+            extent: elem.extent.resolve(styles),
+        }],
+    ))
+};
+
+const OVERLINE_RULE: ShowFn<OverlineElem> = |elem, _, styles| {
+    Ok(elem.body.clone().set(
+        TextElem::deco,
+        smallvec![Decoration {
+            line: DecoLine::Overline {
+                stroke: elem.stroke.resolve(styles).unwrap_or_default(),
+                offset: elem.offset.resolve(styles),
+                evade: elem.evade.get(styles),
+                background: elem.background.get(styles),
+            },
+            extent: elem.extent.resolve(styles),
+        }],
+    ))
+};
+
+const STRIKE_RULE: ShowFn<StrikeElem> = |elem, _, styles| {
+    Ok(elem.body.clone().set(
+        TextElem::deco,
+        smallvec![Decoration {
+            // Note that we do not support evade option for strikethrough.
+            line: DecoLine::Strikethrough {
+                stroke: elem.stroke.resolve(styles).unwrap_or_default(),
+                offset: elem.offset.resolve(styles),
+                background: elem.background.get(styles),
+            },
+            extent: elem.extent.resolve(styles),
+        }],
+    ))
+};
+
+const HIGHLIGHT_RULE: ShowFn<HighlightElem> = |elem, _, styles| {
+    Ok(elem.body.clone().set(
+        TextElem::deco,
+        smallvec![Decoration {
+            line: DecoLine::Highlight {
+                fill: elem.fill.get_cloned(styles),
+                stroke: elem
+                    .stroke
+                    .resolve(styles)
+                    .unwrap_or_default()
+                    .map(|stroke| stroke.map(Stroke::unwrap_or_default)),
+                top_edge: elem.top_edge.get(styles),
+                bottom_edge: elem.bottom_edge.get(styles),
+                radius: elem.radius.resolve(styles).unwrap_or_default(),
+            },
+            extent: elem.extent.resolve(styles),
+        }],
+    ))
+};
+
+const SMALLCAPS_RULE: ShowFn<SmallcapsElem> = |elem, _, styles| {
+    let sc = if elem.all.get(styles) { Smallcaps::All } else { Smallcaps::Minuscules };
+    Ok(elem.body.clone().set(TextElem::smallcaps, Some(sc)))
+};
+
+const RAW_RULE: ShowFn<RawElem> = |elem, _, styles| {
+    let lines = elem.lines.as_deref().unwrap_or_default();
+
+    let mut seq = EcoVec::with_capacity((2 * lines.len()).saturating_sub(1));
+    for (i, line) in lines.iter().enumerate() {
+        if i != 0 {
+            seq.push(LinebreakElem::shared().clone());
+        }
+
+        seq.push(line.clone().pack());
+    }
+
+    let mut realized = Content::sequence(seq);
+
+    if elem.block.get(styles) {
+        // Align the text before inserting it into the block.
+        realized = realized.aligned(elem.align.get(styles).into());
+        realized = BlockElem::new()
+            .with_body(Some(BlockBody::Content(realized)))
+            .pack()
+            .spanned(elem.span());
+    }
+
+    Ok(realized)
+};
+
+const RAW_LINE_RULE: ShowFn<RawLine> = |elem, _, _| Ok(elem.body.clone());
+
+const ALIGN_RULE: ShowFn<AlignElem> =
+    |elem, _, styles| Ok(elem.body.clone().aligned(elem.alignment.get(styles)));
+
+const PAD_RULE: ShowFn<PadElem> = |elem, _, _| {
+    Ok(BlockElem::multi_layouter(elem.clone(), crate::pad::layout_pad)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const COLUMNS_RULE: ShowFn<ColumnsElem> = |elem, _, _| {
+    Ok(BlockElem::multi_layouter(elem.clone(), crate::flow::layout_columns)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const STACK_RULE: ShowFn<StackElem> = |elem, _, _| {
+    Ok(BlockElem::multi_layouter(elem.clone(), crate::stack::layout_stack)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const GRID_RULE: ShowFn<GridElem> = |elem, _, _| {
+    Ok(BlockElem::multi_layouter(elem.clone(), crate::grid::layout_grid)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const GRID_CELL_RULE: ShowFn<GridCell> = |elem, _, styles| {
+    show_cell(elem.body.clone(), elem.inset.get(styles), elem.align.get(styles))
+};
+
+/// Function with common code to display a grid cell or table cell.
+fn show_cell(
+    mut body: Content,
+    inset: Smart<Sides<Option<Rel<Length>>>>,
+    align: Smart<Alignment>,
+) -> SourceResult<Content> {
+    let inset = inset.unwrap_or_default().map(Option::unwrap_or_default);
+
+    if inset != Sides::default() {
+        // Only pad if some inset is not 0pt.
+        // Avoids a bug where using .padded() in any way inside Show causes
+        // alignment in align(...) to break.
+        body = body.padded(inset);
+    }
+
+    if let Smart::Custom(alignment) = align {
+        body = body.aligned(alignment);
+    }
+
+    Ok(body)
+}
+
+const MOVE_RULE: ShowFn<MoveElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::transforms::layout_move)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const SCALE_RULE: ShowFn<ScaleElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::transforms::layout_scale)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const ROTATE_RULE: ShowFn<RotateElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::transforms::layout_rotate)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const SKEW_RULE: ShowFn<SkewElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::transforms::layout_skew)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const REPEAT_RULE: ShowFn<RepeatElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::repeat::layout_repeat)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const HIDE_RULE: ShowFn<HideElem> =
+    |elem, _, _| Ok(elem.body.clone().set(HideElem::hidden, true));
+
+const LAYOUT_RULE: ShowFn<LayoutElem> = |elem, _, _| {
+    Ok(BlockElem::multi_layouter(
+        elem.clone(),
+        |elem, engine, locator, styles, regions| {
+            // Gets the current region's base size, which will be the size of the
+            // outer container, or of the page if there is no such container.
+            let Size { x, y } = regions.base();
+            let loc = elem.location().unwrap();
+            let context = Context::new(Some(loc), Some(styles));
+            let result = elem
+                .func
+                .call(engine, context.track(), [dict! { "width" => x, "height" => y }])?
+                .display();
+            crate::flow::layout_fragment(engine, &result, locator, styles, regions)
+        },
+    )
+    .pack()
+    .spanned(elem.span()))
+};
+
+const IMAGE_RULE: ShowFn<ImageElem> = |elem, _, styles| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::image::layout_image)
+        .with_width(elem.width.get(styles))
+        .with_height(elem.height.get(styles))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const LINE_RULE: ShowFn<LineElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::shapes::layout_line)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const RECT_RULE: ShowFn<RectElem> = |elem, _, styles| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::shapes::layout_rect)
+        .with_width(elem.width.get(styles))
+        .with_height(elem.height.get(styles))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const SQUARE_RULE: ShowFn<SquareElem> = |elem, _, styles| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::shapes::layout_square)
+        .with_width(elem.width.get(styles))
+        .with_height(elem.height.get(styles))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const ELLIPSE_RULE: ShowFn<EllipseElem> = |elem, _, styles| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::shapes::layout_ellipse)
+        .with_width(elem.width.get(styles))
+        .with_height(elem.height.get(styles))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const CIRCLE_RULE: ShowFn<CircleElem> = |elem, _, styles| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::shapes::layout_circle)
+        .with_width(elem.width.get(styles))
+        .with_height(elem.height.get(styles))
+        .pack()
+        .spanned(elem.span()))
+};
+
+const POLYGON_RULE: ShowFn<PolygonElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::shapes::layout_polygon)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const CURVE_RULE: ShowFn<CurveElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::shapes::layout_curve)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const PATH_RULE: ShowFn<PathElem> = |elem, _, _| {
+    Ok(BlockElem::single_layouter(elem.clone(), crate::shapes::layout_path)
+        .pack()
+        .spanned(elem.span()))
+};
+
+const EQUATION_RULE: ShowFn<EquationElem> = |elem, _, styles| {
+    if elem.block.get(styles) {
+        Ok(BlockElem::multi_layouter(elem.clone(), crate::math::layout_equation_block)
+            .pack()
+            .spanned(elem.span()))
+    } else {
+        Ok(InlineElem::layouter(elem.clone(), crate::math::layout_equation_inline)
+            .pack()
+            .spanned(elem.span()))
+    }
+};
+
+const EMBED_RULE: ShowFn<EmbedElem> = |_, _, _| Ok(Content::empty());

crates/typst-layout/src/shapes.rs

@@ -27,16 +27,20 @@ pub fn layout_line(
     region: Region,
 ) -> SourceResult<Frame> {
     let resolve = |axes: Axes<Rel<Abs>>| axes.zip_map(region.size, Rel::relative_to);
-    let start = resolve(elem.start(styles));
-    let delta = elem.end(styles).map(|end| resolve(end) - start).unwrap_or_else(|| {
-        let length = elem.length(styles);
-        let angle = elem.angle(styles);
-        let x = angle.cos() * length;
-        let y = angle.sin() * length;
-        resolve(Axes::new(x, y))
-    });
+    let start = resolve(elem.start.resolve(styles));
+    let delta = elem
+        .end
+        .resolve(styles)
+        .map(|end| resolve(end) - start)
+        .unwrap_or_else(|| {
+            let length = elem.length.resolve(styles);
+            let angle = elem.angle.get(styles);
+            let x = angle.cos() * length;
+            let y = angle.sin() * length;
+            resolve(Axes::new(x, y))
+        });
 
-    let stroke = elem.stroke(styles).unwrap_or_default();
+    let stroke = elem.stroke.resolve(styles).unwrap_or_default();
     let size = start.max(start + delta).max(Size::zero());
 
     if !size.is_finite() {
@@ -105,7 +109,7 @@ pub fn layout_path(
         add_cubic(from_point, to_point, from, to);
     }
 
-    if elem.closed(styles) {
+    if elem.closed.get(styles) {
         let from = *vertices.last().unwrap(); // We checked that we have at least one element.
         let to = vertices[0];
         let from_point = *points.last().unwrap();
@@ -120,9 +124,9 @@ pub fn layout_path(
     }
 
     // Prepare fill and stroke.
-    let fill = elem.fill(styles);
-    let fill_rule = elem.fill_rule(styles);
-    let stroke = match elem.stroke(styles) {
+    let fill = elem.fill.get_cloned(styles);
+    let fill_rule = elem.fill_rule.get(styles);
+    let stroke = match elem.stroke.resolve(styles) {
         Smart::Auto if fill.is_none() => Some(FixedStroke::default()),
         Smart::Auto => None,
         Smart::Custom(stroke) => stroke.map(Stroke::unwrap_or_default),
@@ -153,19 +157,19 @@ pub fn layout_curve(
     for item in &elem.components {
         match item {
             CurveComponent::Move(element) => {
-                let relative = element.relative(styles);
+                let relative = element.relative.get(styles);
                 let point = builder.resolve_point(element.start, relative);
                 builder.move_(point);
             }
 
             CurveComponent::Line(element) => {
-                let relative = element.relative(styles);
+                let relative = element.relative.get(styles);
                 let point = builder.resolve_point(element.end, relative);
                 builder.line(point);
             }
 
             CurveComponent::Quad(element) => {
-                let relative = element.relative(styles);
+                let relative = element.relative.get(styles);
                 let end = builder.resolve_point(element.end, relative);
                 let control = match element.control {
                     Smart::Auto => {
@@ -178,7 +182,7 @@ pub fn layout_curve(
             }
 
             CurveComponent::Cubic(element) => {
-                let relative = element.relative(styles);
+                let relative = element.relative.get(styles);
                 let end = builder.resolve_point(element.end, relative);
                 let c1 = match element.control_start {
                     Some(Smart::Custom(p)) => builder.resolve_point(p, relative),
@@ -193,7 +197,7 @@ pub fn layout_curve(
             }
 
             CurveComponent::Close(element) => {
-                builder.close(element.mode(styles));
+                builder.close(element.mode.get(styles));
             }
         }
     }
@@ -208,9 +212,9 @@ pub fn layout_curve(
     }
 
     // Prepare fill and stroke.
-    let fill = elem.fill(styles);
-    let fill_rule = elem.fill_rule(styles);
-    let stroke = match elem.stroke(styles) {
+    let fill = elem.fill.get_cloned(styles);
+    let fill_rule = elem.fill_rule.get(styles);
+    let stroke = match elem.stroke.resolve(styles) {
         Smart::Auto if fill.is_none() => Some(FixedStroke::default()),
         Smart::Auto => None,
         Smart::Custom(stroke) => stroke.map(Stroke::unwrap_or_default),
@@ -418,9 +422,9 @@ pub fn layout_polygon(
     }
 
     // Prepare fill and stroke.
-    let fill = elem.fill(styles);
-    let fill_rule = elem.fill_rule(styles);
-    let stroke = match elem.stroke(styles) {
+    let fill = elem.fill.get_cloned(styles);
+    let fill_rule = elem.fill_rule.get(styles);
+    let stroke = match elem.stroke.resolve(styles) {
         Smart::Auto if fill.is_none() => Some(FixedStroke::default()),
         Smart::Auto => None,
         Smart::Custom(stroke) => stroke.map(Stroke::unwrap_or_default),
@@ -459,12 +463,12 @@ pub fn layout_rect(
         styles,
         region,
         ShapeKind::Rect,
-        elem.body(styles),
-        elem.fill(styles),
-        elem.stroke(styles),
-        elem.inset(styles),
-        elem.outset(styles),
-        elem.radius(styles),
+        elem.body.get_ref(styles),
+        elem.fill.get_cloned(styles),
+        elem.stroke.resolve(styles),
+        elem.inset.resolve(styles),
+        elem.outset.resolve(styles),
+        elem.radius.resolve(styles),
         elem.span(),
     )
 }
@@ -484,12 +488,12 @@ pub fn layout_square(
         styles,
         region,
         ShapeKind::Square,
-        elem.body(styles),
-        elem.fill(styles),
-        elem.stroke(styles),
-        elem.inset(styles),
-        elem.outset(styles),
-        elem.radius(styles),
+        elem.body.get_ref(styles),
+        elem.fill.get_cloned(styles),
+        elem.stroke.resolve(styles),
+        elem.inset.resolve(styles),
+        elem.outset.resolve(styles),
+        elem.radius.resolve(styles),
         elem.span(),
     )
 }
@@ -509,11 +513,11 @@ pub fn layout_ellipse(
         styles,
         region,
         ShapeKind::Ellipse,
-        elem.body(styles),
-        elem.fill(styles),
-        elem.stroke(styles).map(|s| Sides::splat(Some(s))),
-        elem.inset(styles),
-        elem.outset(styles),
+        elem.body.get_ref(styles),
+        elem.fill.get_cloned(styles),
+        elem.stroke.resolve(styles).map(|s| Sides::splat(Some(s))),
+        elem.inset.resolve(styles),
+        elem.outset.resolve(styles),
         Corners::splat(None),
         elem.span(),
     )
@@ -534,11 +538,11 @@ pub fn layout_circle(
         styles,
         region,
         ShapeKind::Circle,
-        elem.body(styles),
-        elem.fill(styles),
-        elem.stroke(styles).map(|s| Sides::splat(Some(s))),
-        elem.inset(styles),
-        elem.outset(styles),
+        elem.body.get_ref(styles),
+        elem.fill.get_cloned(styles),
+        elem.stroke.resolve(styles).map(|s| Sides::splat(Some(s))),
+        elem.inset.resolve(styles),
+        elem.outset.resolve(styles),
         Corners::splat(None),
         elem.span(),
     )

crates/typst-layout/src/stack.rs

@@ -19,12 +19,12 @@ pub fn layout_stack(
     regions: Regions,
 ) -> SourceResult<Fragment> {
     let mut layouter =
-        StackLayouter::new(elem.span(), elem.dir(styles), locator, styles, regions);
+        StackLayouter::new(elem.span(), elem.dir.get(styles), locator, styles, regions);
 
     let axis = layouter.dir.axis();
 
     // Spacing to insert before the next block.
-    let spacing = elem.spacing(styles);
+    let spacing = elem.spacing.get(styles);
     let mut deferred = None;
 
     for child in &elem.children {
@@ -167,11 +167,11 @@ impl<'a> StackLayouter<'a> {
 
         // Block-axis alignment of the `AlignElem` is respected by stacks.
         let align = if let Some(align) = block.to_packed::<AlignElem>() {
-            align.alignment(styles)
+            align.alignment.get(styles)
         } else if let Some(styled) = block.to_packed::<StyledElem>() {
-            AlignElem::alignment_in(styles.chain(&styled.styles))
+            styles.chain(&styled.styles).get(AlignElem::alignment)
         } else {
-            AlignElem::alignment_in(styles)
+            styles.get(AlignElem::alignment)
         }
         .resolve(styles);
 

crates/typst-layout/src/transforms.rs

@@ -20,7 +20,7 @@ pub fn layout_move(
     region: Region,
 ) -> SourceResult<Frame> {
     let mut frame = crate::layout_frame(engine, &elem.body, locator, styles, region)?;
-    let delta = Axes::new(elem.dx(styles), elem.dy(styles)).resolve(styles);
+    let delta = Axes::new(elem.dx.resolve(styles), elem.dy.resolve(styles));
     let delta = delta.zip_map(region.size, Rel::relative_to);
     frame.translate(delta.to_point());
     Ok(frame)
@@ -35,8 +35,8 @@ pub fn layout_rotate(
     styles: StyleChain,
     region: Region,
 ) -> SourceResult<Frame> {
-    let angle = elem.angle(styles);
-    let align = elem.origin(styles).resolve(styles);
+    let angle = elem.angle.get(styles);
+    let align = elem.origin.resolve(styles);
 
     // Compute the new region's approximate size.
     let is_finite = region.size.is_finite();
@@ -55,7 +55,7 @@ pub fn layout_rotate(
         &elem.body,
         Transform::rotate(angle),
         align,
-        elem.reflow(styles),
+        elem.reflow.get(styles),
     )
 }
 
@@ -83,8 +83,8 @@ pub fn layout_scale(
         styles,
         &elem.body,
         Transform::scale(scale.x, scale.y),
-        elem.origin(styles).resolve(styles),
-        elem.reflow(styles),
+        elem.origin.resolve(styles),
+        elem.reflow.get(styles),
     )
 }
 
@@ -121,13 +121,13 @@ fn resolve_scale(
     });
 
     let x = resolve_axis(
-        elem.x(styles),
+        elem.x.get(styles),
         || size.as_ref().map(|size| size.x).map_err(Clone::clone),
         styles,
     )?;
 
     let y = resolve_axis(
-        elem.y(styles),
+        elem.y.get(styles),
         || size.as_ref().map(|size| size.y).map_err(Clone::clone),
         styles,
     )?;
@@ -152,9 +152,9 @@ pub fn layout_skew(
     styles: StyleChain,
     region: Region,
 ) -> SourceResult<Frame> {
-    let ax = elem.ax(styles);
-    let ay = elem.ay(styles);
-    let align = elem.origin(styles).resolve(styles);
+    let ax = elem.ax.get(styles);
+    let ay = elem.ay.get(styles);
+    let align = elem.origin.resolve(styles);
 
     // Compute the new region's approximate size.
     let size = if region.size.is_finite() {
@@ -172,7 +172,7 @@ pub fn layout_skew(
         &elem.body,
         Transform::skew(ax, ay),
         align,
-        elem.reflow(styles),
+        elem.reflow.get(styles),
     )
 }
 

crates/typst-library/src/foundations/content/element.rs

@@ -2,52 +2,54 @@ use std::any::TypeId;
 use std::cmp::Ordering;
 use std::fmt::{self, Debug};
 use std::hash::Hash;
-use std::ptr::NonNull;
-use std::sync::LazyLock;
+use std::sync::OnceLock;
 
 use ecow::EcoString;
 use smallvec::SmallVec;
-#[doc(inline)]
-pub use typst_macros::elem;
 use typst_utils::Static;
 
 use crate::diag::SourceResult;
 use crate::engine::Engine;
 use crate::foundations::{
-    cast, Args, Content, Dict, FieldAccessError, Func, ParamInfo, Repr, Scope, Selector,
-    StyleChain, Styles, Value,
+    cast, Args, Content, ContentVtable, FieldAccessError, Func, ParamInfo, Repr, Scope,
+    Selector, StyleChain, Styles, Value,
 };
 use crate::text::{Lang, Region};
 
 /// A document element.
 #[derive(Copy, Clone, Eq, PartialEq, Hash)]
-pub struct Element(Static<NativeElementData>);
+pub struct Element(Static<ContentVtable>);
 
 impl Element {
     /// Get the element for `T`.
-    pub fn of<T: NativeElement>() -> Self {
-        T::elem()
+    pub const fn of<T: NativeElement>() -> Self {
+        T::ELEM
+    }
+
+    /// Get the element for `T`.
+    pub const fn from_vtable(vtable: &'static ContentVtable) -> Self {
+        Self(Static(vtable))
     }
 
     /// The element's normal name (e.g. `enum`).
     pub fn name(self) -> &'static str {
-        self.0.name
+        self.vtable().name
     }
 
     /// The element's title case name, for use in documentation
     /// (e.g. `Numbered List`).
     pub fn title(&self) -> &'static str {
-        self.0.title
+        self.vtable().title
     }
 
     /// Documentation for the element (as Markdown).
     pub fn docs(&self) -> &'static str {
-        self.0.docs
+        self.vtable().docs
     }
 
     /// Search keywords for the element.
     pub fn keywords(&self) -> &'static [&'static str] {
-        self.0.keywords
+        self.vtable().keywords
     }
 
     /// Construct an instance of this element.
@@ -56,12 +58,12 @@ impl Element {
         engine: &mut Engine,
         args: &mut Args,
     ) -> SourceResult<Content> {
-        (self.0.construct)(engine, args)
+        (self.vtable().construct)(engine, args)
     }
 
     /// Execute the set rule for the element and return the resulting style map.
     pub fn set(self, engine: &mut Engine, mut args: Args) -> SourceResult<Styles> {
-        let styles = (self.0.set)(engine, &mut args)?;
+        let styles = (self.vtable().set)(engine, &mut args)?;
         args.finish()?;
         Ok(styles)
     }
@@ -77,12 +79,7 @@ impl Element {
     /// Whether the element has the given capability where the capability is
     /// given by a `TypeId`.
     pub fn can_type_id(self, type_id: TypeId) -> bool {
-        (self.0.vtable)(type_id).is_some()
-    }
-
-    /// The VTable for capabilities dispatch.
-    pub fn vtable(self) -> fn(of: TypeId) -> Option<NonNull<()>> {
-        self.0.vtable
+        (self.vtable().capability)(type_id).is_some()
     }
 
     /// Create a selector for this element.
@@ -98,12 +95,29 @@ impl Element {
 
     /// The element's associated scope of sub-definition.
     pub fn scope(&self) -> &'static Scope {
-        &(self.0).0.scope
+        (self.vtable().store)().scope.get_or_init(|| (self.vtable().scope)())
     }
 
     /// Details about the element's fields.
     pub fn params(&self) -> &'static [ParamInfo] {
-        &(self.0).0.params
+        (self.vtable().store)().params.get_or_init(|| {
+            self.vtable()
+                .fields
+                .iter()
+                .filter(|field| !field.synthesized)
+                .map(|field| ParamInfo {
+                    name: field.name,
+                    docs: field.docs,
+                    input: (field.input)(),
+                    default: field.default,
+                    positional: field.positional,
+                    named: !field.positional,
+                    variadic: field.variadic,
+                    required: field.required,
+                    settable: field.settable,
+                })
+                .collect()
+        })
     }
 
     /// Extract the field ID for the given field name.
@@ -111,7 +125,7 @@ impl Element {
         if name == "label" {
             return Some(255);
         }
-        (self.0.field_id)(name)
+        (self.vtable().field_id)(name)
     }
 
     /// Extract the field name for the given field ID.
@@ -119,7 +133,7 @@ impl Element {
         if id == 255 {
             return Some("label");
         }
-        (self.0.field_name)(id)
+        self.vtable().field(id).map(|data| data.name)
     }
 
     /// Extract the value of the field for the given field ID and style chain.
@@ -128,12 +142,20 @@ impl Element {
         id: u8,
         styles: StyleChain,
     ) -> Result<Value, FieldAccessError> {
-        (self.0.field_from_styles)(id, styles)
+        self.vtable()
+            .field(id)
+            .and_then(|field| (field.get_from_styles)(styles))
+            .ok_or(FieldAccessError::Unknown)
     }
 
     /// The element's local name, if any.
     pub fn local_name(&self, lang: Lang, region: Option<Region>) -> Option<&'static str> {
-        (self.0).0.local_name.map(|f| f(lang, region))
+        self.vtable().local_name.map(|f| f(lang, region))
+    }
+
+    /// Retrieves the element's vtable for dynamic dispatch.
+    pub(super) fn vtable(&self) -> &'static ContentVtable {
+        (self.0).0
     }
 }
 
@@ -167,84 +189,34 @@ cast! {
     v: Func => v.element().ok_or("expected element")?,
 }
 
-/// A Typst element that is defined by a native Rust type.
-pub trait NativeElement:
-    Debug
-    + Clone
-    + PartialEq
-    + Hash
-    + Construct
-    + Set
-    + Capable
-    + Fields
-    + Repr
-    + Send
-    + Sync
-    + 'static
-{
-    /// Get the element for the native Rust element.
-    fn elem() -> Element
-    where
-        Self: Sized,
-    {
-        Element::from(Self::data())
-    }
-
-    /// Pack the element into type-erased content.
-    fn pack(self) -> Content
-    where
-        Self: Sized,
-    {
-        Content::new(self)
-    }
-
-    /// Get the element data for the native Rust element.
-    fn data() -> &'static NativeElementData
-    where
-        Self: Sized;
+/// Lazily initialized data for an element.
+#[derive(Default)]
+pub struct LazyElementStore {
+    pub scope: OnceLock<Scope>,
+    pub params: OnceLock<Vec<ParamInfo>>,
 }
 
-/// Used to cast an element to a trait object for a trait it implements.
+impl LazyElementStore {
+    /// Create an empty store.
+    pub const fn new() -> Self {
+        Self { scope: OnceLock::new(), params: OnceLock::new() }
+    }
+}
+
+/// A Typst element that is defined by a native Rust type.
 ///
 /// # Safety
-/// If the `vtable` function returns `Some(p)`, then `p` must be a valid pointer
-/// to a vtable of `Packed<Self>` w.r.t to the trait `C` where `capability` is
-/// `TypeId::of::<dyn C>()`.
-pub unsafe trait Capable {
-    /// Get the pointer to the vtable for the given capability / trait.
-    fn vtable(capability: TypeId) -> Option<NonNull<()>>;
-}
+/// `ELEM` must hold the correct `Element` for `Self`.
+pub unsafe trait NativeElement:
+    Debug + Clone + Hash + Construct + Set + Send + Sync + 'static
+{
+    /// The associated element.
+    const ELEM: Element;
 
-/// Defines how fields of an element are accessed.
-pub trait Fields {
-    /// An enum with the fields of the element.
-    type Enum
-    where
-        Self: Sized;
-
-    /// Whether the element has the given field set.
-    fn has(&self, id: u8) -> bool;
-
-    /// Get the field with the given field ID.
-    fn field(&self, id: u8) -> Result<Value, FieldAccessError>;
-
-    /// Get the field with the given ID in the presence of styles.
-    fn field_with_styles(
-        &self,
-        id: u8,
-        styles: StyleChain,
-    ) -> Result<Value, FieldAccessError>;
-
-    /// Get the field with the given ID from the styles.
-    fn field_from_styles(id: u8, styles: StyleChain) -> Result<Value, FieldAccessError>
-    where
-        Self: Sized;
-
-    /// Resolve all fields with the styles and save them in-place.
-    fn materialize(&mut self, styles: StyleChain);
-
-    /// Get the fields of the element.
-    fn fields(&self) -> Dict;
+    /// Pack the element into type-erased content.
+    fn pack(self) -> Content {
+        Content::new(self)
+    }
 }
 
 /// An element's constructor function.
@@ -266,48 +238,6 @@ pub trait Set {
         Self: Sized;
 }
 
-/// Defines a native element.
-#[derive(Debug)]
-pub struct NativeElementData {
-    /// The element's normal name (e.g. `align`), as exposed to Typst.
-    pub name: &'static str,
-    /// The element's title case name (e.g. `Align`).
-    pub title: &'static str,
-    /// The documentation for this element as a string.
-    pub docs: &'static str,
-    /// A list of alternate search terms for this element.
-    pub keywords: &'static [&'static str],
-    /// The constructor for this element (see [`Construct`]).
-    pub construct: fn(&mut Engine, &mut Args) -> SourceResult<Content>,
-    /// Executes this element's set rule (see [`Set`]).
-    pub set: fn(&mut Engine, &mut Args) -> SourceResult<Styles>,
-    /// Gets the vtable for one of this element's capabilities
-    /// (see [`Capable`]).
-    pub vtable: fn(capability: TypeId) -> Option<NonNull<()>>,
-    /// Gets the numeric index of this field by its name.
-    pub field_id: fn(name: &str) -> Option<u8>,
-    /// Gets the name of a field by its numeric index.
-    pub field_name: fn(u8) -> Option<&'static str>,
-    /// Get the field with the given ID in the presence of styles (see [`Fields`]).
-    pub field_from_styles: fn(u8, StyleChain) -> Result<Value, FieldAccessError>,
-    /// Gets the localized name for this element (see [`LocalName`][crate::text::LocalName]).
-    pub local_name: Option<fn(Lang, Option<Region>) -> &'static str>,
-    pub scope: LazyLock<Scope>,
-    /// A list of parameter information for each field.
-    pub params: LazyLock<Vec<ParamInfo>>,
-}
-
-impl From<&'static NativeElementData> for Element {
-    fn from(data: &'static NativeElementData) -> Self {
-        Self(Static(data))
-    }
-}
-
-cast! {
-    &'static NativeElementData,
-    self => Element::from(self).into_value(),
-}
-
 /// Synthesize fields on an element. This happens before execution of any show
 /// rule.
 pub trait Synthesize {
@@ -316,12 +246,6 @@ pub trait Synthesize {
         -> SourceResult<()>;
 }
 
-/// Defines a built-in show rule for an element.
-pub trait Show {
-    /// Execute the base recipe for this element.
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content>;
-}
-
 /// Defines built-in show set rules for an element.
 ///
 /// This is a bit more powerful than a user-defined show-set because it can
@@ -331,3 +255,9 @@ pub trait ShowSet {
     /// that should work even in the face of a user-defined show rule.
     fn show_set(&self, styles: StyleChain) -> Styles;
 }
+
+/// Tries to extract the plain-text representation of the element.
+pub trait PlainText {
+    /// Write this element's plain text into the given buffer.
+    fn plain_text(&self, text: &mut EcoString);
+}

crates/typst-library/src/foundations/content/field.rs

@@ -0,0 +1,564 @@
+use std::fmt::{self, Debug};
+use std::hash::Hash;
+use std::marker::PhantomData;
+use std::sync::OnceLock;
+
+use ecow::{eco_format, EcoString};
+
+use crate::foundations::{
+    Container, Content, FieldVtable, Fold, FoldFn, IntoValue, NativeElement, Packed,
+    Property, Reflect, Repr, Resolve, StyleChain,
+};
+
+/// An accessor for the `I`-th field of the element `E`. Values of this type are
+/// generated for each field of an element can be used to interact with this
+/// field programmatically, for example to access the style chain, as in
+/// `styles.get(TextElem::size)`.
+#[derive(Copy, Clone)]
+pub struct Field<E: NativeElement, const I: u8>(pub PhantomData<E>);
+
+impl<E: NativeElement, const I: u8> Field<E, I> {
+    /// Creates a new zero-sized accessor.
+    pub const fn new() -> Self {
+        Self(PhantomData)
+    }
+
+    /// The index of the projected field.
+    pub const fn index(self) -> u8 {
+        I
+    }
+
+    /// Creates a dynamic property instance for this field.
+    ///
+    /// Prefer [`Content::set`] or
+    /// [`Styles::set`](crate::foundations::Styles::set) when working with
+    /// existing content or style value.
+    pub fn set(self, value: E::Type) -> Property
+    where
+        E: SettableProperty<I>,
+        E::Type: Debug + Clone + Hash + Send + Sync + 'static,
+    {
+        Property::new(self, value)
+    }
+}
+
+impl<E: NativeElement, const I: u8> Default for Field<E, I> {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+/// A field that is present on every instance of the element.
+pub trait RequiredField<const I: u8>: NativeElement {
+    type Type: Clone;
+
+    const FIELD: RequiredFieldData<Self, I>;
+}
+
+/// Metadata and routines for a [`RequiredField`].
+pub struct RequiredFieldData<E: RequiredField<I>, const I: u8> {
+    name: &'static str,
+    docs: &'static str,
+    get: fn(&E) -> &E::Type,
+}
+
+impl<E: RequiredField<I>, const I: u8> RequiredFieldData<E, I> {
+    /// Creates the data from its parts. This is called in the `#[elem]` macro.
+    pub const fn new(
+        name: &'static str,
+        docs: &'static str,
+        get: fn(&E) -> &E::Type,
+    ) -> Self {
+        Self { name, docs, get }
+    }
+
+    /// Creates the vtable for a `#[required]` field.
+    pub const fn vtable() -> FieldVtable<Packed<E>>
+    where
+        E: RequiredField<I>,
+        E::Type: Reflect + IntoValue + PartialEq,
+    {
+        FieldVtable {
+            name: E::FIELD.name,
+            docs: E::FIELD.docs,
+            positional: true,
+            required: true,
+            variadic: false,
+            settable: false,
+            synthesized: false,
+            input: || <E::Type as Reflect>::input(),
+            default: None,
+            has: |_| true,
+            get: |elem| Some((E::FIELD.get)(elem).clone().into_value()),
+            get_with_styles: |elem, _| Some((E::FIELD.get)(elem).clone().into_value()),
+            get_from_styles: |_| None,
+            materialize: |_, _| {},
+            eq: |a, b| (E::FIELD.get)(a) == (E::FIELD.get)(b),
+        }
+    }
+
+    /// Creates the vtable for a `#[variadic]` field.
+    pub const fn vtable_variadic() -> FieldVtable<Packed<E>>
+    where
+        E: RequiredField<I>,
+        E::Type: Container + IntoValue + PartialEq,
+        <E::Type as Container>::Inner: Reflect,
+    {
+        FieldVtable {
+            name: E::FIELD.name,
+            docs: E::FIELD.docs,
+            positional: true,
+            required: true,
+            variadic: true,
+            settable: false,
+            synthesized: false,
+            input: || <<E::Type as Container>::Inner as Reflect>::input(),
+            default: None,
+            has: |_| true,
+            get: |elem| Some((E::FIELD.get)(elem).clone().into_value()),
+            get_with_styles: |elem, _| Some((E::FIELD.get)(elem).clone().into_value()),
+            get_from_styles: |_| None,
+            materialize: |_, _| {},
+            eq: |a, b| (E::FIELD.get)(a) == (E::FIELD.get)(b),
+        }
+    }
+}
+
+/// A field that is initially unset, but may be set through a
+/// [`Synthesize`](crate::foundations::Synthesize) implementation.
+pub trait SynthesizedField<const I: u8>: NativeElement {
+    type Type: Clone;
+
+    const FIELD: SynthesizedFieldData<Self, I>;
+}
+
+/// Metadata and routines for a [`SynthesizedField`].
+pub struct SynthesizedFieldData<E: SynthesizedField<I>, const I: u8> {
+    name: &'static str,
+    docs: &'static str,
+    get: fn(&E) -> &Option<E::Type>,
+}
+
+impl<E: SynthesizedField<I>, const I: u8> SynthesizedFieldData<E, I> {
+    /// Creates the data from its parts. This is called in the `#[elem]` macro.
+    pub const fn new(
+        name: &'static str,
+        docs: &'static str,
+        get: fn(&E) -> &Option<E::Type>,
+    ) -> Self {
+        Self { name, docs, get }
+    }
+
+    /// Creates type-erased metadata and routines for a `#[synthesized]` field.
+    pub const fn vtable() -> FieldVtable<Packed<E>>
+    where
+        E: SynthesizedField<I>,
+        E::Type: Reflect + IntoValue + PartialEq,
+    {
+        FieldVtable {
+            name: E::FIELD.name,
+            docs: E::FIELD.docs,
+            positional: false,
+            required: false,
+            variadic: false,
+            settable: false,
+            synthesized: true,
+            input: || <E::Type as Reflect>::input(),
+            default: None,
+            has: |elem| (E::FIELD.get)(elem).is_some(),
+            get: |elem| (E::FIELD.get)(elem).clone().map(|v| v.into_value()),
+            get_with_styles: |elem, _| {
+                (E::FIELD.get)(elem).clone().map(|v| v.into_value())
+            },
+            get_from_styles: |_| None,
+            materialize: |_, _| {},
+            // Synthesized fields don't affect equality.
+            eq: |_, _| true,
+        }
+    }
+}
+
+/// A field that is not actually there. It's only visible in the docs.
+pub trait ExternalField<const I: u8>: NativeElement {
+    type Type;
+
+    const FIELD: ExternalFieldData<Self, I>;
+}
+
+/// Metadata for an [`ExternalField`].
+pub struct ExternalFieldData<E: ExternalField<I>, const I: u8> {
+    name: &'static str,
+    docs: &'static str,
+    default: fn() -> E::Type,
+}
+
+impl<E: ExternalField<I>, const I: u8> ExternalFieldData<E, I> {
+    /// Creates the data from its parts. This is called in the `#[elem]` macro.
+    pub const fn new(
+        name: &'static str,
+        docs: &'static str,
+        default: fn() -> E::Type,
+    ) -> Self {
+        Self { name, docs, default }
+    }
+
+    /// Creates type-erased metadata and routines for an `#[external]` field.
+    pub const fn vtable() -> FieldVtable<Packed<E>>
+    where
+        E: ExternalField<I>,
+        E::Type: Reflect + IntoValue,
+    {
+        FieldVtable {
+            name: E::FIELD.name,
+            docs: E::FIELD.docs,
+            positional: false,
+            required: false,
+            variadic: false,
+            settable: false,
+            synthesized: false,
+            input: || <E::Type as Reflect>::input(),
+            default: Some(|| (E::FIELD.default)().into_value()),
+            has: |_| false,
+            get: |_| None,
+            get_with_styles: |_, _| None,
+            get_from_styles: |_| None,
+            materialize: |_, _| {},
+            eq: |_, _| true,
+        }
+    }
+}
+
+/// A field that has a default value and can be configured via a set rule, but
+/// can also present on elements and be present in the constructor.
+pub trait SettableField<const I: u8>: NativeElement {
+    type Type: Clone;
+
+    const FIELD: SettableFieldData<Self, I>;
+}
+
+/// Metadata and routines for a [`SettableField`].
+pub struct SettableFieldData<E: SettableField<I>, const I: u8> {
+    get: fn(&E) -> &Settable<E, I>,
+    get_mut: fn(&mut E) -> &mut Settable<E, I>,
+    property: SettablePropertyData<E, I>,
+}
+
+impl<E: SettableField<I>, const I: u8> SettableFieldData<E, I> {
+    /// Creates the data from its parts. This is called in the `#[elem]` macro.
+    pub const fn new(
+        name: &'static str,
+        docs: &'static str,
+        positional: bool,
+        get: fn(&E) -> &Settable<E, I>,
+        get_mut: fn(&mut E) -> &mut Settable<E, I>,
+        default: fn() -> E::Type,
+        slot: fn() -> &'static OnceLock<E::Type>,
+    ) -> Self {
+        Self {
+            get,
+            get_mut,
+            property: SettablePropertyData::new(name, docs, positional, default, slot),
+        }
+    }
+
+    /// Ensures that the property is folded on every access. See the
+    /// documentation of the [`Fold`] trait for more details.
+    pub const fn with_fold(mut self) -> Self
+    where
+        E::Type: Fold,
+    {
+        self.property.fold = Some(E::Type::fold);
+        self
+    }
+
+    /// Creates type-erased metadata and routines for a normal settable field.
+    pub const fn vtable() -> FieldVtable<Packed<E>>
+    where
+        E: SettableField<I>,
+        E::Type: Reflect + IntoValue + PartialEq,
+    {
+        FieldVtable {
+            name: E::FIELD.property.name,
+            docs: E::FIELD.property.docs,
+            positional: E::FIELD.property.positional,
+            required: false,
+            variadic: false,
+            settable: true,
+            synthesized: false,
+            input: || <E::Type as Reflect>::input(),
+            default: Some(|| E::default().into_value()),
+            has: |elem| (E::FIELD.get)(elem).is_set(),
+            get: |elem| (E::FIELD.get)(elem).as_option().clone().map(|v| v.into_value()),
+            get_with_styles: |elem, styles| {
+                Some((E::FIELD.get)(elem).get_cloned(styles).into_value())
+            },
+            get_from_styles: |styles| {
+                Some(styles.get_cloned::<E, I>(Field::new()).into_value())
+            },
+            materialize: |elem, styles| {
+                if !(E::FIELD.get)(elem).is_set() {
+                    (E::FIELD.get_mut)(elem).set(styles.get_cloned::<E, I>(Field::new()));
+                }
+            },
+            eq: |a, b| (E::FIELD.get)(a).as_option() == (E::FIELD.get)(b).as_option(),
+        }
+    }
+}
+
+/// A field that has a default value and can be configured via a set rule, but
+/// is never present on elements.
+///
+/// This is provided for all `SettableField` impls through a blanket impl. In
+/// the case of `#[ghost]` fields, which only live in the style chain and not in
+/// elements, it is also implemented manually.
+pub trait SettableProperty<const I: u8>: NativeElement {
+    type Type: Clone;
+
+    const FIELD: SettablePropertyData<Self, I>;
+    const FOLD: Option<FoldFn<Self::Type>> = Self::FIELD.fold;
+
+    /// Produces an instance of the property's default value.
+    fn default() -> Self::Type {
+        // Avoid recreating an expensive instance over and over, but also
+        // avoid unnecessary lazy initialization for cheap types.
+        if std::mem::needs_drop::<Self::Type>() {
+            Self::default_ref().clone()
+        } else {
+            (Self::FIELD.default)()
+        }
+    }
+
+    /// Produces a static reference to this property's default value.
+    fn default_ref() -> &'static Self::Type {
+        (Self::FIELD.slot)().get_or_init(Self::FIELD.default)
+    }
+}
+
+impl<T, const I: u8> SettableProperty<I> for T
+where
+    T: SettableField<I>,
+{
+    type Type = <Self as SettableField<I>>::Type;
+
+    const FIELD: SettablePropertyData<Self, I> =
+        <Self as SettableField<I>>::FIELD.property;
+}
+
+/// Metadata and routines for a [`SettableProperty`].
+pub struct SettablePropertyData<E: SettableProperty<I>, const I: u8> {
+    name: &'static str,
+    docs: &'static str,
+    positional: bool,
+    default: fn() -> E::Type,
+    slot: fn() -> &'static OnceLock<E::Type>,
+    fold: Option<FoldFn<E::Type>>,
+}
+
+impl<E: SettableProperty<I>, const I: u8> SettablePropertyData<E, I> {
+    /// Creates the data from its parts. This is called in the `#[elem]` macro.
+    pub const fn new(
+        name: &'static str,
+        docs: &'static str,
+        positional: bool,
+        default: fn() -> E::Type,
+        slot: fn() -> &'static OnceLock<E::Type>,
+    ) -> Self {
+        Self { name, docs, positional, default, slot, fold: None }
+    }
+
+    /// Ensures that the property is folded on every access. See the
+    /// documentation of the [`Fold`] trait for more details.
+    pub const fn with_fold(self) -> Self
+    where
+        E::Type: Fold,
+    {
+        Self { fold: Some(E::Type::fold), ..self }
+    }
+
+    /// Creates type-erased metadata and routines for a `#[ghost]` field.
+    pub const fn vtable() -> FieldVtable<Packed<E>>
+    where
+        E: SettableProperty<I>,
+        E::Type: Reflect + IntoValue + PartialEq,
+    {
+        FieldVtable {
+            name: E::FIELD.name,
+            docs: E::FIELD.docs,
+            positional: E::FIELD.positional,
+            required: false,
+            variadic: false,
+            settable: true,
+            synthesized: false,
+            input: || <E::Type as Reflect>::input(),
+            default: Some(|| E::default().into_value()),
+            has: |_| false,
+            get: |_| None,
+            get_with_styles: |_, styles| {
+                Some(styles.get_cloned::<E, I>(Field::new()).into_value())
+            },
+            get_from_styles: |styles| {
+                Some(styles.get_cloned::<E, I>(Field::new()).into_value())
+            },
+            materialize: |_, _| {},
+            eq: |_, _| true,
+        }
+    }
+}
+
+/// A settable property that can be accessed by reference (because it is not
+/// folded).
+pub trait RefableProperty<const I: u8>: SettableProperty<I> {}
+
+/// A settable field of an element.
+///
+/// The field can be in two states: Unset or present.
+///
+/// See [`StyleChain`] for more details about the available accessor methods.
+#[derive(Copy, Clone, Hash)]
+pub struct Settable<E: NativeElement, const I: u8>(Option<E::Type>)
+where
+    E: SettableProperty<I>;
+
+impl<E: NativeElement, const I: u8> Settable<E, I>
+where
+    E: SettableProperty<I>,
+{
+    /// Creates a new unset instance.
+    pub fn new() -> Self {
+        Self(None)
+    }
+
+    /// Sets the instance to a value.
+    pub fn set(&mut self, value: E::Type) {
+        self.0 = Some(value);
+    }
+
+    /// Clears the value from the instance.
+    pub fn unset(&mut self) {
+        self.0 = None;
+    }
+
+    /// Views the type as an [`Option`] which is `Some` if the type is set
+    /// and `None` if it is unset.
+    pub fn as_option(&self) -> &Option<E::Type> {
+        &self.0
+    }
+
+    /// Views the type as a mutable [`Option`].
+    pub fn as_option_mut(&mut self) -> &mut Option<E::Type> {
+        &mut self.0
+    }
+
+    /// Whether the field is set.
+    pub fn is_set(&self) -> bool {
+        self.0.is_some()
+    }
+
+    /// Retrieves the value given styles. The styles are used if the value is
+    /// unset.
+    pub fn get<'a>(&'a self, styles: StyleChain<'a>) -> E::Type
+    where
+        E::Type: Copy,
+    {
+        self.get_cloned(styles)
+    }
+
+    /// Retrieves and clones the value given styles. The styles are used if the
+    /// value is unset or if it needs folding.
+    pub fn get_cloned<'a>(&'a self, styles: StyleChain<'a>) -> E::Type {
+        if let Some(fold) = E::FOLD {
+            let mut res = styles.get_cloned::<E, I>(Field::new());
+            if let Some(value) = &self.0 {
+                res = fold(value.clone(), res);
+            }
+            res
+        } else if let Some(value) = &self.0 {
+            value.clone()
+        } else {
+            styles.get_cloned::<E, I>(Field::new())
+        }
+    }
+
+    /// Retrieves a reference to the value given styles. The styles are used if
+    /// the value is unset.
+    pub fn get_ref<'a>(&'a self, styles: StyleChain<'a>) -> &'a E::Type
+    where
+        E: RefableProperty<I>,
+    {
+        if let Some(value) = &self.0 {
+            value
+        } else {
+            styles.get_ref::<E, I>(Field::new())
+        }
+    }
+
+    /// Retrieves the value and then immediately [resolves](Resolve) it.
+    pub fn resolve<'a>(&'a self, styles: StyleChain<'a>) -> <E::Type as Resolve>::Output
+    where
+        E::Type: Resolve,
+    {
+        self.get_cloned(styles).resolve(styles)
+    }
+}
+
+impl<E: NativeElement, const I: u8> Debug for Settable<E, I>
+where
+    E: SettableProperty<I>,
+    E::Type: Debug,
+{
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl<E: NativeElement, const I: u8> Default for Settable<E, I>
+where
+    E: SettableProperty<I>,
+{
+    fn default() -> Self {
+        Self(None)
+    }
+}
+
+impl<E: NativeElement, const I: u8> From<Option<E::Type>> for Settable<E, I>
+where
+    E: SettableProperty<I>,
+{
+    fn from(value: Option<E::Type>) -> Self {
+        Self(value)
+    }
+}
+
+/// An error arising when trying to access a field of content.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
+pub enum FieldAccessError {
+    Unknown,
+    Unset,
+}
+
+impl FieldAccessError {
+    /// Formats the error message given the content and the field name.
+    #[cold]
+    pub fn message(self, content: &Content, field: &str) -> EcoString {
+        let elem_name = content.elem().name();
+        match self {
+            FieldAccessError::Unknown => {
+                eco_format!("{elem_name} does not have field {}", field.repr())
+            }
+            FieldAccessError::Unset => {
+                eco_format!(
+                    "field {} in {elem_name} is not known at this point",
+                    field.repr()
+                )
+            }
+        }
+    }
+
+    /// Formats the error message for an `at` calls without a default value.
+    #[cold]
+    pub fn message_no_default(self, content: &Content, field: &str) -> EcoString {
+        let mut msg = self.message(content, field);
+        msg.push_str(" and no default was specified");
+        msg
+    }
+}

crates/typst-library/src/foundations/content/mod.rs

@@ -1,23 +1,33 @@
-use std::any::TypeId;
+mod element;
+mod field;
+mod packed;
+mod raw;
+mod vtable;
+
+pub use self::element::*;
+pub use self::field::*;
+pub use self::packed::Packed;
+pub use self::vtable::{ContentVtable, FieldVtable};
+#[doc(inline)]
+pub use typst_macros::elem;
+
 use std::fmt::{self, Debug, Formatter};
-use std::hash::{Hash, Hasher};
+use std::hash::Hash;
 use std::iter::{self, Sum};
-use std::marker::PhantomData;
-use std::ops::{Add, AddAssign, ControlFlow, Deref, DerefMut};
-use std::sync::Arc;
+use std::ops::{Add, AddAssign, ControlFlow};
 
 use comemo::Tracked;
 use ecow::{eco_format, EcoString};
 use serde::{Serialize, Serializer};
+
 use typst_syntax::Span;
-use typst_utils::{fat, singleton, LazyHash, SmallBitSet};
+use typst_utils::singleton;
 
 use crate::diag::{SourceResult, StrResult};
 use crate::engine::Engine;
 use crate::foundations::{
-    elem, func, scope, ty, Context, Dict, Element, Fields, IntoValue, Label,
-    NativeElement, Recipe, RecipeIndex, Repr, Selector, Str, Style, StyleChain, Styles,
-    Value,
+    func, repr, scope, ty, Context, Dict, IntoValue, Label, Property, Recipe,
+    RecipeIndex, Repr, Selector, Str, Style, StyleChain, Styles, Value,
 };
 use crate::introspection::Location;
 use crate::layout::{AlignElem, Alignment, Axes, Length, MoveElem, PadElem, Rel, Sides};
@@ -68,43 +78,14 @@ use crate::text::UnderlineElem;
 /// elements the content is composed of and what fields they have.
 /// Alternatively, you can inspect the output of the [`repr`] function.
 #[ty(scope, cast)]
-#[derive(Clone, Hash)]
-#[allow(clippy::derived_hash_with_manual_eq)]
-pub struct Content {
-    /// The partially element-dependent inner data.
-    inner: Arc<Inner<dyn Bounds>>,
-    /// The element's source code location.
-    span: Span,
-}
-
-/// The inner representation behind the `Arc`.
-#[derive(Hash)]
-struct Inner<T: ?Sized + 'static> {
-    /// An optional label attached to the element.
-    label: Option<Label>,
-    /// The element's location which identifies it in the layouted output.
-    location: Option<Location>,
-    /// Manages the element during realization.
-    /// - If bit 0 is set, the element is prepared.
-    /// - If bit n is set, the element is guarded against the n-th show rule
-    ///   recipe from the top of the style chain (counting from 1).
-    lifecycle: SmallBitSet,
-    /// The element's raw data.
-    elem: LazyHash<T>,
-}
+#[derive(Clone, PartialEq, Hash)]
+#[repr(transparent)]
+pub struct Content(raw::RawContent);
 
 impl Content {
     /// Creates a new content from an element.
     pub fn new<T: NativeElement>(elem: T) -> Self {
-        Self {
-            inner: Arc::new(Inner {
-                label: None,
-                location: None,
-                lifecycle: SmallBitSet::new(),
-                elem: elem.into(),
-            }),
-            span: Span::detached(),
-        }
+        Self(raw::RawContent::new(elem))
     }
 
     /// Creates a empty sequence content.
@@ -114,25 +95,25 @@ impl Content {
 
     /// Get the element of this content.
     pub fn elem(&self) -> Element {
-        self.inner.elem.dyn_elem()
+        self.0.elem()
     }
 
     /// Get the span of the content.
     pub fn span(&self) -> Span {
-        self.span
+        self.0.span()
     }
 
     /// Set the span of the content.
     pub fn spanned(mut self, span: Span) -> Self {
-        if self.span.is_detached() {
-            self.span = span;
+        if self.0.span().is_detached() {
+            *self.0.span_mut() = span;
         }
         self
     }
 
     /// Get the label of the content.
     pub fn label(&self) -> Option<Label> {
-        self.inner.label
+        self.0.meta().label
     }
 
     /// Attach a label to the content.
@@ -143,7 +124,7 @@ impl Content {
 
     /// Set the label of the content.
     pub fn set_label(&mut self, label: Label) {
-        self.make_mut().label = Some(label);
+        self.0.meta_mut().label = Some(label);
     }
 
     /// Assigns a location to the content.
@@ -159,28 +140,28 @@ impl Content {
 
     /// Set the location of the content.
     pub fn set_location(&mut self, location: Location) {
-        self.make_mut().location = Some(location);
+        self.0.meta_mut().location = Some(location);
     }
 
     /// Check whether a show rule recipe is disabled.
     pub fn is_guarded(&self, index: RecipeIndex) -> bool {
-        self.inner.lifecycle.contains(index.0)
+        self.0.meta().lifecycle.contains(index.0)
     }
 
     /// Disable a show rule recipe.
     pub fn guarded(mut self, index: RecipeIndex) -> Self {
-        self.make_mut().lifecycle.insert(index.0);
+        self.0.meta_mut().lifecycle.insert(index.0);
         self
     }
 
     /// Whether this content has already been prepared.
     pub fn is_prepared(&self) -> bool {
-        self.inner.lifecycle.contains(0)
+        self.0.meta().lifecycle.contains(0)
     }
 
     /// Mark this content as prepared.
     pub fn mark_prepared(&mut self) {
-        self.make_mut().lifecycle.insert(0);
+        self.0.meta_mut().lifecycle.insert(0);
     }
 
     /// Get a field by ID.
@@ -198,9 +179,14 @@ impl Content {
                 return Ok(label.into_value());
             }
         }
-        match styles {
-            Some(styles) => self.inner.elem.field_with_styles(id, styles),
-            None => self.inner.elem.field(id),
+
+        match self.0.handle().field(id) {
+            Some(handle) => match styles {
+                Some(styles) => handle.get_with_styles(styles),
+                None => handle.get(),
+            }
+            .ok_or(FieldAccessError::Unset),
+            None => Err(FieldAccessError::Unknown),
         }
     }
 
@@ -215,8 +201,11 @@ impl Content {
                 .map(|label| label.into_value())
                 .ok_or(FieldAccessError::Unknown);
         }
-        let id = self.elem().field_id(name).ok_or(FieldAccessError::Unknown)?;
-        self.get(id, None)
+
+        match self.elem().field_id(name).and_then(|id| self.0.handle().field(id)) {
+            Some(handle) => handle.get().ok_or(FieldAccessError::Unset),
+            None => Err(FieldAccessError::Unknown),
+        }
     }
 
     /// Get a field by ID, returning a missing field error if it does not exist.
@@ -240,7 +229,9 @@ impl Content {
 
     /// Resolve all fields with the styles and save them in-place.
     pub fn materialize(&mut self, styles: StyleChain) {
-        self.make_mut().elem.materialize(styles);
+        for id in 0..self.elem().vtable().fields.len() as u8 {
+            self.0.handle_mut().field(id).unwrap().materialize(styles);
+        }
     }
 
     /// Create a new sequence element from multiples elements.
@@ -257,7 +248,7 @@ impl Content {
 
     /// Whether the contained element is of type `T`.
     pub fn is<T: NativeElement>(&self) -> bool {
-        self.inner.elem.dyn_type_id() == TypeId::of::<T>()
+        self.0.is::<T>()
     }
 
     /// Downcasts the element to a packed value.
@@ -280,16 +271,6 @@ impl Content {
         self.into_packed::<T>().map(Packed::unpack)
     }
 
-    /// Makes sure the content is not shared and returns a mutable reference to
-    /// the inner data.
-    fn make_mut(&mut self) -> &mut Inner<dyn Bounds> {
-        let arc = &mut self.inner;
-        if Arc::strong_count(arc) > 1 || Arc::weak_count(arc) > 0 {
-            *self = arc.elem.dyn_clone(arc, self.span);
-        }
-        Arc::get_mut(&mut self.inner).unwrap()
-    }
-
     /// Whether the contained element has the given capability.
     pub fn can<C>(&self) -> bool
     where
@@ -304,13 +285,7 @@ impl Content {
     where
         C: ?Sized + 'static,
     {
-        // Safety: The vtable comes from the `Capable` implementation which
-        // guarantees to return a matching vtable for `Packed<T>` and `C`.
-        // Since any `Packed<T>` is a repr(transparent) `Content`, we can also
-        // use a `*const Content` pointer.
-        let vtable = self.elem().vtable()(TypeId::of::<C>())?;
-        let data = self as *const Content as *const ();
-        Some(unsafe { &*fat::from_raw_parts(data, vtable.as_ptr()) })
+        self.0.with::<C>()
     }
 
     /// Cast to a mutable trait object if the contained element has the given
@@ -319,18 +294,7 @@ impl Content {
     where
         C: ?Sized + 'static,
     {
-        // Safety: The vtable comes from the `Capable` implementation which
-        // guarantees to return a matching vtable for `Packed<T>` and `C`.
-        // Since any `Packed<T>` is a repr(transparent) `Content`, we can also
-        // use a `*const Content` pointer.
-        //
-        // The resulting trait object contains an `&mut Packed<T>`. We do _not_
-        // need to ensure that we hold the only reference to the `Arc` here
-        // because `Packed<T>`'s DerefMut impl will take care of that if
-        // mutable access is required.
-        let vtable = self.elem().vtable()(TypeId::of::<C>())?;
-        let data = self as *mut Content as *mut ();
-        Some(unsafe { &mut *fat::from_raw_parts_mut(data, vtable.as_ptr()) })
+        self.0.with_mut::<C>()
     }
 
     /// Whether the content is an empty sequence.
@@ -372,6 +336,15 @@ impl Content {
         Self::sequence(std::iter::repeat_with(|| self.clone()).take(count))
     }
 
+    /// Sets a style property on the content.
+    pub fn set<E, const I: u8>(self, field: Field<E, I>, value: E::Type) -> Self
+    where
+        E: SettableProperty<I>,
+        E::Type: Debug + Clone + Hash + Send + Sync + 'static,
+    {
+        self.styled(Property::new(field, value))
+    }
+
     /// Style this content with a style entry.
     pub fn styled(mut self, style: impl Into<Style>) -> Self {
         if let Some(style_elem) = self.to_packed_mut::<StyledElem>() {
@@ -476,7 +449,7 @@ impl Content {
 
         // Call f on the element itself before recursively iterating its fields.
         f(self.clone())?;
-        for (_, value) in self.inner.elem.fields() {
+        for (_, value) in self.fields() {
             walk_value(value, f)?;
         }
         ControlFlow::Continue(())
@@ -504,12 +477,12 @@ impl Content {
 
     /// Link the content somewhere.
     pub fn linked(self, dest: Destination) -> Self {
-        self.styled(LinkElem::set_current(Some(dest)))
+        self.set(LinkElem::current, Some(dest))
     }
 
     /// Set alignments for this content.
     pub fn aligned(self, align: Alignment) -> Self {
-        self.styled(AlignElem::set_alignment(align))
+        self.set(AlignElem::alignment, align)
     }
 
     /// Pad this content at the sides.
@@ -562,7 +535,10 @@ impl Content {
             return false;
         };
 
-        self.inner.elem.has(id)
+        match self.0.handle().field(id) {
+            Some(field) => field.has(),
+            None => false,
+        }
     }
 
     /// Access the specified field on the content. Returns the default value if
@@ -592,7 +568,12 @@ impl Content {
     /// ```
     #[func]
     pub fn fields(&self) -> Dict {
-        let mut dict = self.inner.elem.fields();
+        let mut dict = Dict::new();
+        for field in self.0.handle().fields() {
+            if let Some(value) = field.get() {
+                dict.insert(field.name.into(), value);
+            }
+        }
         if let Some(label) = self.label() {
             dict.insert("label".into(), label.into_value());
         }
@@ -605,7 +586,7 @@ impl Content {
     /// used with [counters]($counter), [state] and [queries]($query).
     #[func]
     pub fn location(&self) -> Option<Location> {
-        self.inner.location
+        self.0.meta().location
     }
 }
 
@@ -617,7 +598,7 @@ impl Default for Content {
 
 impl Debug for Content {
     fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        self.inner.elem.fmt(f)
+        self.0.fmt(f)
     }
 }
 
@@ -627,16 +608,22 @@ impl<T: NativeElement> From<T> for Content {
     }
 }
 
-impl PartialEq for Content {
-    fn eq(&self, other: &Self) -> bool {
-        // Additional short circuit for different elements.
-        self.elem() == other.elem() && self.inner.elem.dyn_eq(other)
-    }
-}
-
 impl Repr for Content {
     fn repr(&self) -> EcoString {
-        self.inner.elem.repr()
+        self.0.handle().repr().unwrap_or_else(|| {
+            let fields = self
+                .0
+                .handle()
+                .fields()
+                .filter_map(|field| field.get().map(|v| (field.name, v.repr())))
+                .map(|(name, value)| eco_format!("{name}: {value}"))
+                .collect::<Vec<_>>();
+            eco_format!(
+                "{}{}",
+                self.elem().name(),
+                repr::pretty_array_like(&fields, false),
+            )
+        })
     }
 }
 
@@ -717,190 +704,8 @@ impl Serialize for Content {
     }
 }
 
-/// The trait that combines all the other traits into a trait object.
-trait Bounds: Debug + Repr + Fields + Send + Sync + 'static {
-    fn dyn_type_id(&self) -> TypeId;
-    fn dyn_elem(&self) -> Element;
-    fn dyn_clone(&self, inner: &Inner<dyn Bounds>, span: Span) -> Content;
-    fn dyn_hash(&self, hasher: &mut dyn Hasher);
-    fn dyn_eq(&self, other: &Content) -> bool;
-}
-
-impl<T: NativeElement> Bounds for T {
-    fn dyn_type_id(&self) -> TypeId {
-        TypeId::of::<Self>()
-    }
-
-    fn dyn_elem(&self) -> Element {
-        Self::elem()
-    }
-
-    fn dyn_clone(&self, inner: &Inner<dyn Bounds>, span: Span) -> Content {
-        Content {
-            inner: Arc::new(Inner {
-                label: inner.label,
-                location: inner.location,
-                lifecycle: inner.lifecycle.clone(),
-                elem: LazyHash::reuse(self.clone(), &inner.elem),
-            }),
-            span,
-        }
-    }
-
-    fn dyn_hash(&self, mut state: &mut dyn Hasher) {
-        TypeId::of::<Self>().hash(&mut state);
-        self.hash(&mut state);
-    }
-
-    fn dyn_eq(&self, other: &Content) -> bool {
-        let Some(other) = other.to_packed::<Self>() else {
-            return false;
-        };
-        *self == **other
-    }
-}
-
-impl Hash for dyn Bounds {
-    fn hash<H: Hasher>(&self, state: &mut H) {
-        self.dyn_hash(state);
-    }
-}
-
-/// A packed element of a static type.
-#[derive(Clone, PartialEq, Hash)]
-#[repr(transparent)]
-pub struct Packed<T: NativeElement>(
-    /// Invariant: Must be of type `T`.
-    Content,
-    PhantomData<T>,
-);
-
-impl<T: NativeElement> Packed<T> {
-    /// Pack element while retaining its static type.
-    pub fn new(element: T) -> Self {
-        // Safety: The element is known to be of type `T`.
-        Packed(element.pack(), PhantomData)
-    }
-
-    /// Try to cast type-erased content into a statically known packed element.
-    pub fn from_ref(content: &Content) -> Option<&Self> {
-        if content.is::<T>() {
-            // Safety:
-            // - We have checked the type.
-            // - Packed<T> is repr(transparent).
-            return Some(unsafe { std::mem::transmute::<&Content, &Packed<T>>(content) });
-        }
-        None
-    }
-
-    /// Try to cast type-erased content into a statically known packed element.
-    pub fn from_mut(content: &mut Content) -> Option<&mut Self> {
-        if content.is::<T>() {
-            // Safety:
-            // - We have checked the type.
-            // - Packed<T> is repr(transparent).
-            return Some(unsafe {
-                std::mem::transmute::<&mut Content, &mut Packed<T>>(content)
-            });
-        }
-        None
-    }
-
-    /// Try to cast type-erased content into a statically known packed element.
-    pub fn from_owned(content: Content) -> Result<Self, Content> {
-        if content.is::<T>() {
-            // Safety:
-            // - We have checked the type.
-            // - Packed<T> is repr(transparent).
-            return Ok(unsafe { std::mem::transmute::<Content, Packed<T>>(content) });
-        }
-        Err(content)
-    }
-
-    /// Pack back into content.
-    pub fn pack(self) -> Content {
-        self.0
-    }
-
-    /// Extract the raw underlying element.
-    pub fn unpack(self) -> T {
-        // This function doesn't yet need owned self, but might in the future.
-        (*self).clone()
-    }
-
-    /// The element's span.
-    pub fn span(&self) -> Span {
-        self.0.span()
-    }
-
-    /// Set the span of the element.
-    pub fn spanned(self, span: Span) -> Self {
-        Self(self.0.spanned(span), PhantomData)
-    }
-
-    /// Accesses the label of the element.
-    pub fn label(&self) -> Option<Label> {
-        self.0.label()
-    }
-
-    /// Accesses the location of the element.
-    pub fn location(&self) -> Option<Location> {
-        self.0.location()
-    }
-
-    /// Sets the location of the element.
-    pub fn set_location(&mut self, location: Location) {
-        self.0.set_location(location);
-    }
-}
-
-impl<T: NativeElement> AsRef<T> for Packed<T> {
-    fn as_ref(&self) -> &T {
-        self
-    }
-}
-
-impl<T: NativeElement> AsMut<T> for Packed<T> {
-    fn as_mut(&mut self) -> &mut T {
-        self
-    }
-}
-
-impl<T: NativeElement> Deref for Packed<T> {
-    type Target = T;
-
-    fn deref(&self) -> &Self::Target {
-        // Safety:
-        // - Packed<T> guarantees that the content trait object wraps
-        //   an element of type `T`.
-        // - This downcast works the same way as dyn Any's does. We can't reuse
-        //   that one because we don't want to pay the cost for every deref.
-        let elem = &*self.0.inner.elem;
-        unsafe { &*(elem as *const dyn Bounds as *const T) }
-    }
-}
-
-impl<T: NativeElement> DerefMut for Packed<T> {
-    fn deref_mut(&mut self) -> &mut Self::Target {
-        // Safety:
-        // - Packed<T> guarantees that the content trait object wraps
-        //   an element of type `T`.
-        // - We have guaranteed unique access thanks to `make_mut`.
-        // - This downcast works the same way as dyn Any's does. We can't reuse
-        //   that one because we don't want to pay the cost for every deref.
-        let elem = &mut *self.0.make_mut().elem;
-        unsafe { &mut *(elem as *mut dyn Bounds as *mut T) }
-    }
-}
-
-impl<T: NativeElement + Debug> Debug for Packed<T> {
-    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
-        self.0.fmt(f)
-    }
-}
-
 /// A sequence of content.
-#[elem(Debug, Repr, PartialEq)]
+#[elem(Debug, Repr)]
 pub struct SequenceElem {
     /// The elements.
     #[required]
@@ -922,19 +727,13 @@ impl Default for SequenceElem {
     }
 }
 
-impl PartialEq for SequenceElem {
-    fn eq(&self, other: &Self) -> bool {
-        self.children.iter().eq(other.children.iter())
-    }
-}
-
 impl Repr for SequenceElem {
     fn repr(&self) -> EcoString {
         if self.children.is_empty() {
             "[]".into()
         } else {
             let elements = crate::foundations::repr::pretty_array_like(
-                &self.children.iter().map(|c| c.inner.elem.repr()).collect::<Vec<_>>(),
+                &self.children.iter().map(|c| c.repr()).collect::<Vec<_>>(),
                 false,
             );
             eco_format!("sequence{}", elements)
@@ -974,49 +773,8 @@ impl Repr for StyledElem {
     }
 }
 
-/// Tries to extract the plain-text representation of the element.
-pub trait PlainText {
-    /// Write this element's plain text into the given buffer.
-    fn plain_text(&self, text: &mut EcoString);
-}
-
-/// An error arising when trying to access a field of content.
-#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
-pub enum FieldAccessError {
-    Unknown,
-    Unset,
-    Internal,
-}
-
-impl FieldAccessError {
-    /// Formats the error message given the content and the field name.
-    #[cold]
-    pub fn message(self, content: &Content, field: &str) -> EcoString {
-        let elem_name = content.elem().name();
-        match self {
-            FieldAccessError::Unknown => {
-                eco_format!("{elem_name} does not have field {}", field.repr())
-            }
-            FieldAccessError::Unset => {
-                eco_format!(
-                    "field {} in {elem_name} is not known at this point",
-                    field.repr()
-                )
-            }
-            FieldAccessError::Internal => {
-                eco_format!(
-                    "internal error when accessing field {} in {elem_name} – this is a bug",
-                    field.repr()
-                )
-            }
-        }
-    }
-
-    /// Formats the error message for an `at` calls without a default value.
-    #[cold]
-    pub fn message_no_default(self, content: &Content, field: &str) -> EcoString {
-        let mut msg = self.message(content, field);
-        msg.push_str(" and no default was specified");
-        msg
+impl<T: NativeElement> IntoValue for T {
+    fn into_value(self) -> Value {
+        Value::Content(self.pack())
     }
 }

crates/typst-library/src/foundations/content/packed.rs

@@ -0,0 +1,147 @@
+use std::fmt::{self, Debug, Formatter};
+use std::hash::{Hash, Hasher};
+use std::marker::PhantomData;
+use std::ops::{Deref, DerefMut};
+
+use typst_syntax::Span;
+
+use crate::foundations::{Content, Label, NativeElement};
+use crate::introspection::Location;
+
+/// A packed element of a static type.
+#[derive(Clone)]
+#[repr(transparent)]
+pub struct Packed<T: NativeElement>(
+    /// Invariant: Must be of type `T`.
+    Content,
+    PhantomData<T>,
+);
+
+impl<T: NativeElement> Packed<T> {
+    /// Pack element while retaining its static type.
+    pub fn new(element: T) -> Self {
+        // Safety: The element is known to be of type `T`.
+        Packed(element.pack(), PhantomData)
+    }
+
+    /// Try to cast type-erased content into a statically known packed element.
+    pub fn from_ref(content: &Content) -> Option<&Self> {
+        if content.is::<T>() {
+            // Safety:
+            // - We have checked the type.
+            // - Packed<T> is repr(transparent).
+            return Some(unsafe { std::mem::transmute::<&Content, &Packed<T>>(content) });
+        }
+        None
+    }
+
+    /// Try to cast type-erased content into a statically known packed element.
+    pub fn from_mut(content: &mut Content) -> Option<&mut Self> {
+        if content.is::<T>() {
+            // Safety:
+            // - We have checked the type.
+            // - Packed<T> is repr(transparent).
+            return Some(unsafe {
+                std::mem::transmute::<&mut Content, &mut Packed<T>>(content)
+            });
+        }
+        None
+    }
+
+    /// Try to cast type-erased content into a statically known packed element.
+    pub fn from_owned(content: Content) -> Result<Self, Content> {
+        if content.is::<T>() {
+            // Safety:
+            // - We have checked the type.
+            // - Packed<T> is repr(transparent).
+            return Ok(unsafe { std::mem::transmute::<Content, Packed<T>>(content) });
+        }
+        Err(content)
+    }
+
+    /// Pack back into content.
+    pub fn pack(self) -> Content {
+        self.0
+    }
+
+    /// Extract the raw underlying element.
+    pub fn unpack(self) -> T {
+        // This function doesn't yet need owned self, but might in the future.
+        (*self).clone()
+    }
+
+    /// The element's span.
+    pub fn span(&self) -> Span {
+        self.0.span()
+    }
+
+    /// Set the span of the element.
+    pub fn spanned(self, span: Span) -> Self {
+        Self(self.0.spanned(span), PhantomData)
+    }
+
+    /// Accesses the label of the element.
+    pub fn label(&self) -> Option<Label> {
+        self.0.label()
+    }
+
+    /// Accesses the location of the element.
+    pub fn location(&self) -> Option<Location> {
+        self.0.location()
+    }
+
+    /// Sets the location of the element.
+    pub fn set_location(&mut self, location: Location) {
+        self.0.set_location(location);
+    }
+
+    pub fn as_content(&self) -> &Content {
+        &self.0
+    }
+}
+
+impl<T: NativeElement> AsRef<T> for Packed<T> {
+    fn as_ref(&self) -> &T {
+        self
+    }
+}
+
+impl<T: NativeElement> AsMut<T> for Packed<T> {
+    fn as_mut(&mut self) -> &mut T {
+        self
+    }
+}
+
+impl<T: NativeElement> Deref for Packed<T> {
+    type Target = T;
+
+    fn deref(&self) -> &Self::Target {
+        // Safety: Packed<T> guarantees that the content is of element type `T`.
+        unsafe { (self.0).0.data::<T>() }
+    }
+}
+
+impl<T: NativeElement> DerefMut for Packed<T> {
+    fn deref_mut(&mut self) -> &mut Self::Target {
+        // Safety: Packed<T> guarantees that the content is of element type `T`.
+        unsafe { (self.0).0.data_mut::<T>() }
+    }
+}
+
+impl<T: NativeElement + Debug> Debug for Packed<T> {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        self.0.fmt(f)
+    }
+}
+
+impl<T: NativeElement> PartialEq for Packed<T> {
+    fn eq(&self, other: &Self) -> bool {
+        self.0 == other.0
+    }
+}
+
+impl<T: NativeElement> Hash for Packed<T> {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.0.hash(state);
+    }
+}

crates/typst-library/src/foundations/content/raw.rs

@@ -0,0 +1,426 @@
+use std::any::TypeId;
+use std::fmt::{self, Debug, Formatter};
+use std::hash::{Hash, Hasher};
+use std::ptr::NonNull;
+use std::sync::atomic::{self, AtomicUsize, Ordering};
+
+use typst_syntax::Span;
+use typst_utils::{fat, HashLock, SmallBitSet};
+
+use super::vtable;
+use crate::foundations::{Element, Label, NativeElement, Packed};
+use crate::introspection::Location;
+
+/// The raw, low-level implementation of content.
+///
+/// The `ptr` + `elem` fields implement a fat pointer setup similar to an
+/// `Arc<Inner<dyn Trait>>`, but in a manual way, allowing us to have a custom
+/// [vtable].
+pub struct RawContent {
+    /// A type-erased pointer to an allocation containing two things:
+    /// - A header that is the same for all elements
+    /// - Element-specific `data` that holds the specific element
+    ///
+    /// This pointer is valid for both a `Header` and an `Inner<E>` where
+    /// `E::ELEM == self.elem` and can be freely cast between both. This is
+    /// possible because
+    /// - `Inner<E>` is `repr(C)`
+    /// - The first field of `Inner<E>` is `Header`
+    /// - ISO/IEC 9899:TC2 C standard § 6.7.2.1 - 13 states that a pointer to a
+    ///   structure "points to its initial member" with no padding at the start
+    ptr: NonNull<Header>,
+    /// Describes which kind of element this content holds. This is used for
+    ///
+    /// - Direct comparisons, e.g. `is::<HeadingElem>()`
+    /// - Behavior: An `Element` is just a pointer to a `ContentVtable`
+    ///   containing not just data, but also function pointers for various
+    ///   element-specific operations that can be performed
+    ///
+    /// It is absolutely crucial that `elem == <E as NativeElement>::ELEM` for
+    /// `Inner<E>` pointed to by `ptr`. Otherwise, things will go very wrong
+    /// since we'd be using the wrong vtable.
+    elem: Element,
+    /// The content's span.
+    span: Span,
+}
+
+/// The allocated part of an element's representation.
+///
+/// This is `repr(C)` to ensure that a pointer to the whole structure may be
+/// cast to a pointer to its first field.
+#[repr(C)]
+struct Inner<E> {
+    /// It is crucial that this is the first field because we cast between
+    /// pointers to `Inner<E>` and pointers to `Header`. See the documentation
+    /// of `RawContent::ptr` for more details.
+    header: Header,
+    /// The element struct. E.g. `E = HeadingElem`.
+    data: E,
+}
+
+/// The header that is shared by all elements.
+struct Header {
+    /// The element's reference count. This works just like for `Arc`.
+    /// Unfortunately, we have to reimplement reference counting because we
+    /// have a custom fat pointer and `Arc` wouldn't know how to drop its
+    /// contents. Something with `ManuallyDrop<Arc<_>>` might also work, but at
+    /// that point we're not gaining much and with the way it's implemented now
+    /// we can also skip the unnecessary weak reference count.
+    refs: AtomicUsize,
+    /// Metadata for the element.
+    meta: Meta,
+    /// A cell for memoizing the hash of just the `data` part of the content.
+    hash: HashLock,
+}
+
+/// Metadata that elements can hold.
+#[derive(Clone, Hash)]
+pub(super) struct Meta {
+    /// An optional label attached to the element.
+    pub label: Option<Label>,
+    /// The element's location which identifies it in the laid-out output.
+    pub location: Option<Location>,
+    /// Manages the element during realization.
+    /// - If bit 0 is set, the element is prepared.
+    /// - If bit n is set, the element is guarded against the n-th show rule
+    ///   recipe from the top of the style chain (counting from 1).
+    pub lifecycle: SmallBitSet,
+}
+
+impl RawContent {
+    /// Creates raw content wrapping an element, with all metadata set to
+    /// default (including a detached span).
+    pub(super) fn new<E: NativeElement>(data: E) -> Self {
+        Self::create(
+            data,
+            Meta {
+                label: None,
+                location: None,
+                lifecycle: SmallBitSet::new(),
+            },
+            HashLock::new(),
+            Span::detached(),
+        )
+    }
+
+    /// Creates and allocates raw content.
+    fn create<E: NativeElement>(data: E, meta: Meta, hash: HashLock, span: Span) -> Self {
+        let raw = Box::into_raw(Box::<Inner<E>>::new(Inner {
+            header: Header { refs: AtomicUsize::new(1), meta, hash },
+            data,
+        }));
+
+        // Safety: `Box` always holds a non-null pointer. See also
+        // `Box::into_non_null` (which is unstable).
+        let non_null = unsafe { NonNull::new_unchecked(raw) };
+
+        // Safety: See `RawContent::ptr`.
+        let ptr = non_null.cast::<Header>();
+
+        Self { ptr, elem: E::ELEM, span }
+    }
+
+    /// Destroys raw content and deallocates.
+    ///
+    /// # Safety
+    /// - The reference count must be zero.
+    /// - The raw content must be be of type `E`.
+    pub(super) unsafe fn drop_impl<E: NativeElement>(&mut self) {
+        debug_assert_eq!(self.header().refs.load(Ordering::Relaxed), 0);
+
+        // Safety:
+        // - The caller guarantees that the content is of type `E`.
+        // - Thus, `ptr` must have been created from `Box<Inner<E>>` (see
+        //   `RawContent::ptr`).
+        // - And to clean it up, we can just reproduce our box.
+        unsafe {
+            let ptr = self.ptr.cast::<Inner<E>>();
+            drop(Box::<Inner<E>>::from_raw(ptr.as_ptr()));
+        }
+    }
+
+    /// Clones a packed element into new raw content.
+    pub(super) fn clone_impl<E: NativeElement>(elem: &Packed<E>) -> Self {
+        let raw = &elem.as_content().0;
+        let header = raw.header();
+        RawContent::create(
+            elem.as_ref().clone(),
+            header.meta.clone(),
+            header.hash.clone(),
+            raw.span,
+        )
+    }
+
+    /// Accesses the header part of the raw content.
+    fn header(&self) -> &Header {
+        // Safety: `self.ptr` is a valid pointer to a header structure.
+        unsafe { self.ptr.as_ref() }
+    }
+
+    /// Mutably accesses the header part of the raw content.
+    fn header_mut(&mut self) -> &mut Header {
+        self.make_unique();
+
+        // Safety:
+        // - `self.ptr` is a valid pointer to a header structure.
+        // - We have unique access to the backing allocation (just ensured).
+        unsafe { self.ptr.as_mut() }
+    }
+
+    /// Retrieves the contained element **without checking that the content is
+    /// of the correct type.**
+    ///
+    /// # Safety
+    /// This must be preceded by a check to [`is`]. The safe API for this is
+    /// [`Content::to_packed`] and the [`Packed`] struct.
+    pub(super) unsafe fn data<E: NativeElement>(&self) -> &E {
+        debug_assert!(self.is::<E>());
+
+        // Safety:
+        // - The caller guarantees that the content is of type `E`.
+        // - `self.ptr` is a valid pointer to an `Inner<E>` (see
+        //   `RawContent::ptr`).
+        unsafe { &self.ptr.cast::<Inner<E>>().as_ref().data }
+    }
+
+    /// Retrieves the contained element mutably **without checking that the
+    /// content is of the correct type.**
+    ///
+    /// Ensures that the element's allocation is unique.
+    ///
+    /// # Safety
+    /// This must be preceded by a check to [`is`]. The safe API for this is
+    /// [`Content::to_packed_mut`] and the [`Packed`] struct.
+    pub(super) unsafe fn data_mut<E: NativeElement>(&mut self) -> &mut E {
+        debug_assert!(self.is::<E>());
+
+        // Ensure that the memoized hash is reset because we may mutate the
+        // element.
+        self.header_mut().hash.reset();
+
+        // Safety:
+        // - The caller guarantees that the content is of type `E`.
+        // - `self.ptr` is a valid pointer to an `Inner<E>` (see
+        //   `RawContent::ptr`).
+        // - We have unique access to the backing allocation (due to header_mut).
+        unsafe { &mut self.ptr.cast::<Inner<E>>().as_mut().data }
+    }
+
+    /// Ensures that we have unique access to the backing allocation by cloning
+    /// if the reference count exceeds 1. This is used before performing
+    /// mutable operations, implementing a clone-on-write scheme.
+    fn make_unique(&mut self) {
+        if self.header().refs.load(Ordering::Relaxed) > 1 {
+            *self = self.handle().clone();
+        }
+    }
+
+    /// Retrieves the element this content is for.
+    pub(super) fn elem(&self) -> Element {
+        self.elem
+    }
+
+    /// Whether this content holds an element of type `E`.
+    pub(super) fn is<E: NativeElement>(&self) -> bool {
+        self.elem == E::ELEM
+    }
+
+    /// Retrieves the content's span.
+    pub(super) fn span(&self) -> Span {
+        self.span
+    }
+
+    /// Retrieves the content's span mutably.
+    pub(super) fn span_mut(&mut self) -> &mut Span {
+        &mut self.span
+    }
+
+    /// Retrieves the content's metadata.
+    pub(super) fn meta(&self) -> &Meta {
+        &self.header().meta
+    }
+
+    /// Retrieves the content's metadata mutably.
+    pub(super) fn meta_mut(&mut self) -> &mut Meta {
+        &mut self.header_mut().meta
+    }
+
+    /// Casts into a trait object for a given trait if the packed element
+    /// implements said trait.
+    pub(super) fn with<C>(&self) -> Option<&C>
+    where
+        C: ?Sized + 'static,
+    {
+        // Safety: The vtable comes from the `Capable` implementation which
+        // guarantees to return a matching vtable for `Packed<T>` and `C`. Since
+        // any `Packed<T>` is repr(transparent) with `Content` and `RawContent`,
+        // we can also use a `*const RawContent` pointer.
+        let vtable = (self.elem.vtable().capability)(TypeId::of::<C>())?;
+        let data = self as *const Self as *const ();
+        Some(unsafe { &*fat::from_raw_parts(data, vtable.as_ptr()) })
+    }
+
+    /// Casts into a mutable trait object for a given trait if the packed
+    /// element implements said trait.
+    pub(super) fn with_mut<C>(&mut self) -> Option<&mut C>
+    where
+        C: ?Sized + 'static,
+    {
+        // Safety: The vtable comes from the `Capable` implementation which
+        // guarantees to return a matching vtable for `Packed<T>` and `C`. Since
+        // any `Packed<T>` is repr(transparent) with `Content` and `RawContent`,
+        // we can also use a `*const Content` pointer.
+        //
+        // The resulting trait object contains an `&mut Packed<T>`. We do _not_
+        // need to ensure that we hold the only reference to the `Arc` here
+        // because `Packed<T>`'s DerefMut impl will take care of that if mutable
+        // access is required.
+        let vtable = (self.elem.vtable().capability)(TypeId::of::<C>())?;
+        let data = self as *mut Self as *mut ();
+        Some(unsafe { &mut *fat::from_raw_parts_mut(data, vtable.as_ptr()) })
+    }
+}
+
+impl RawContent {
+    /// Retrieves the element's vtable.
+    pub(super) fn handle(&self) -> vtable::ContentHandle<&RawContent> {
+        // Safety `self.elem.vtable()` is a matching vtable for `self`.
+        unsafe { vtable::Handle::new(self, self.elem.vtable()) }
+    }
+
+    /// Retrieves the element's vtable.
+    pub(super) fn handle_mut(&mut self) -> vtable::ContentHandle<&mut RawContent> {
+        // Safety `self.elem.vtable()` is a matching vtable for `self`.
+        unsafe { vtable::Handle::new(self, self.elem.vtable()) }
+    }
+
+    /// Retrieves the element's vtable.
+    pub(super) fn handle_pair<'a, 'b>(
+        &'a self,
+        other: &'b RawContent,
+    ) -> Option<vtable::ContentHandle<(&'a RawContent, &'b RawContent)>> {
+        (self.elem == other.elem).then(|| {
+            // Safety:
+            // - `self.elem.vtable()` is a matching vtable for `self`.
+            // - It's also matching for `other` because `self.elem == other.elem`.
+            unsafe { vtable::Handle::new((self, other), self.elem.vtable()) }
+        })
+    }
+}
+
+impl Debug for RawContent {
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        self.handle().debug(f)
+    }
+}
+
+impl Clone for RawContent {
+    fn clone(&self) -> Self {
+        // See Arc's clone impl for details about memory ordering.
+        let prev = self.header().refs.fetch_add(1, Ordering::Relaxed);
+
+        // See Arc's clone impl details about guarding against incredibly
+        // degenerate programs.
+        if prev > isize::MAX as usize {
+            ref_count_overflow(self.ptr, self.elem, self.span);
+        }
+
+        Self { ptr: self.ptr, elem: self.elem, span: self.span }
+    }
+}
+
+impl Drop for RawContent {
+    fn drop(&mut self) {
+        // Drop our ref-count. If there was more than one content before
+        // (including this one), we shouldn't deallocate. See Arc's drop impl
+        // for details about memory ordering.
+        if self.header().refs.fetch_sub(1, Ordering::Release) != 1 {
+            return;
+        }
+
+        // See Arc's drop impl for details.
+        atomic::fence(Ordering::Acquire);
+
+        // Safety:
+        // No other content references the backing allocation (just checked)
+        unsafe {
+            self.handle_mut().drop();
+        }
+    }
+}
+
+impl PartialEq for RawContent {
+    fn eq(&self, other: &Self) -> bool {
+        let Some(handle) = self.handle_pair(other) else { return false };
+        handle
+            .eq()
+            .unwrap_or_else(|| handle.fields().all(|handle| handle.eq()))
+    }
+}
+
+impl Hash for RawContent {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.elem.hash(state);
+        let header = self.header();
+        header.meta.hash(state);
+        header.hash.get_or_insert_with(|| self.handle().hash()).hash(state);
+        self.span.hash(state);
+    }
+}
+
+// Safety:
+// - Works like `Arc`.
+// - `NativeElement` implies `Send` and `Sync`, see below.
+unsafe impl Sync for RawContent {}
+unsafe impl Send for RawContent {}
+
+fn _ensure_send_sync<T: NativeElement>() {
+    fn needs_send_sync<T: Send + Sync>() {}
+    needs_send_sync::<T>();
+}
+
+#[cold]
+fn ref_count_overflow(ptr: NonNull<Header>, elem: Element, span: Span) -> ! {
+    // Drop to decrement the ref count to counter the increment in `clone()`
+    drop(RawContent { ptr, elem, span });
+    panic!("reference count overflow");
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::foundations::{NativeElement, Repr, StyleChain, Value};
+    use crate::introspection::Location;
+    use crate::model::HeadingElem;
+    use crate::text::TextElem;
+
+    #[test]
+    fn test_miri() {
+        let styles = StyleChain::default();
+
+        let mut first = HeadingElem::new(TextElem::packed("Hi!")).with_offset(2).pack();
+        let hash1 = typst_utils::hash128(&first);
+        first.set_location(Location::new(10));
+        let _ = format!("{first:?}");
+        let _ = first.repr();
+
+        assert!(first.is::<HeadingElem>());
+        assert!(!first.is::<TextElem>());
+        assert_eq!(first.to_packed::<TextElem>(), None);
+        assert_eq!(first.location(), Some(Location::new(10)));
+        assert_eq!(first.field_by_name("offset"), Ok(Value::Int(2)));
+        assert!(!first.has("depth".into()));
+
+        let second = first.clone();
+        first.materialize(styles);
+
+        let first_packed = first.to_packed::<HeadingElem>().unwrap();
+        let second_packed = second.to_packed::<HeadingElem>().unwrap();
+
+        assert!(first.has("depth".into()));
+        assert!(!second.has("depth".into()));
+        assert!(first_packed.depth.is_set());
+        assert!(!second_packed.depth.is_set());
+        assert_ne!(first, second);
+        assert_ne!(hash1, typst_utils::hash128(&first));
+    }
+}

crates/typst-library/src/foundations/content/vtable.rs

@@ -0,0 +1,383 @@
+//! A custom [vtable] implementation for content.
+//!
+//! This is similar to what is generated by the Rust compiler under the hood
+//! when using trait objects. However, ours has two key advantages:
+//!
+//! - It can store a _slice_ of sub-vtables for field-specific operations.
+//! - It can store not only methods, but also plain data, allowing us to access
+//!   that data without going through dynamic dispatch.
+//!
+//! Because our vtable pointers are backed by `static` variables, we can also
+//! perform checks for element types by comparing raw vtable pointers giving us
+//! `RawContent::is` without dynamic dispatch.
+//!
+//! Overall, the custom vtable gives us just a little more flexibility and
+//! optimizability than using built-in trait objects.
+//!
+//! Note that all vtable methods receive elements of type `Packed<E>`, but some
+//! only perform actions on the `E` itself, with the shared part kept outside of
+//! the vtable (e.g. `hash`), while some perform the full action (e.g. `clone`
+//! as it needs to return new, fully populated raw content). Which one it is, is
+//! documented for each.
+//!
+//! # Safety
+//! This module contains a lot of `unsafe` keywords, but almost all of it is the
+//! same and quite straightfoward. All function pointers that operate on a
+//! specific element type are marked as unsafe. In combination with `repr(C)`,
+//! this grants us the ability to safely transmute a `ContentVtable<Packed<E>>`
+//! into a `ContentVtable<RawContent>` (or just short `ContentVtable`). Callers
+//! of functions marked as unsafe have to guarantee that the `ContentVtable` was
+//! transmuted from the same `E` as the RawContent was constructed from. The
+//! `Handle` struct provides a safe access layer, moving the guarantee that the
+//! vtable is matching into a single spot.
+//!
+//! [vtable]: https://en.wikipedia.org/wiki/Virtual_method_table
+
+use std::any::TypeId;
+use std::fmt::{self, Debug, Formatter};
+use std::ops::Deref;
+use std::ptr::NonNull;
+
+use ecow::EcoString;
+
+use super::raw::RawContent;
+use crate::diag::SourceResult;
+use crate::engine::Engine;
+use crate::foundations::{
+    Args, CastInfo, Construct, Content, LazyElementStore, NativeElement, NativeScope,
+    Packed, Repr, Scope, Set, StyleChain, Styles, Value,
+};
+use crate::text::{Lang, LocalName, Region};
+
+/// Encapsulates content and a vtable, granting safe access to vtable operations.
+pub(super) struct Handle<T, V: 'static>(T, &'static V);
+
+impl<T, V> Handle<T, V> {
+    /// Produces a new handle from content and a vtable.
+    ///
+    /// # Safety
+    /// The content and vtable must be matching, i.e. `vtable` must be derived
+    /// from the content's vtable.
+    pub(super) unsafe fn new(content: T, vtable: &'static V) -> Self {
+        Self(content, vtable)
+    }
+}
+
+impl<T, V> Deref for Handle<T, V> {
+    type Target = V;
+
+    fn deref(&self) -> &Self::Target {
+        self.1
+    }
+}
+
+pub(super) type ContentHandle<T> = Handle<T, ContentVtable>;
+pub(super) type FieldHandle<T> = Handle<T, FieldVtable>;
+
+/// A vtable for performing element-specific actions on type-erased content.
+/// Also contains general metadata for the specific element.
+#[repr(C)]
+pub struct ContentVtable<T: 'static = RawContent> {
+    /// The element's normal name, as in code.
+    pub(super) name: &'static str,
+    /// The element's title-cased name.
+    pub(super) title: &'static str,
+    /// The element's documentation (as Markdown).
+    pub(super) docs: &'static str,
+    /// Search keywords for the documentation.
+    pub(super) keywords: &'static [&'static str],
+
+    /// Subvtables for all fields of the element.
+    pub(super) fields: &'static [FieldVtable<T>],
+    /// Determines the ID for a field name. This is a separate function instead
+    /// of searching through `fields` so that Rust can generate optimized code
+    /// for the string matching.
+    pub(super) field_id: fn(name: &str) -> Option<u8>,
+
+    /// The constructor of the element.
+    pub(super) construct: fn(&mut Engine, &mut Args) -> SourceResult<Content>,
+    /// The set rule of the element.
+    pub(super) set: fn(&mut Engine, &mut Args) -> SourceResult<Styles>,
+    /// The element's local name in a specific lang-region pairing.
+    pub(super) local_name: Option<fn(Lang, Option<Region>) -> &'static str>,
+    /// Produces the associated [`Scope`] of the element.
+    pub(super) scope: fn() -> Scope,
+    /// If the `capability` function returns `Some(p)`, then `p` must be a valid
+    /// pointer to a native Rust vtable of `Packed<Self>` w.r.t to the trait `C`
+    /// where `capability` is `TypeId::of::<dyn C>()`.
+    pub(super) capability: fn(capability: TypeId) -> Option<NonNull<()>>,
+
+    /// The `Drop` impl (for the whole raw content). The content must have a
+    /// reference count of zero and may not be used anymore after `drop` was
+    /// called.
+    pub(super) drop: unsafe fn(&mut RawContent),
+    /// The `Clone` impl (for the whole raw content).
+    pub(super) clone: unsafe fn(&T) -> RawContent,
+    /// The `Hash` impl (for just the element).
+    pub(super) hash: unsafe fn(&T) -> u128,
+    /// The `Debug` impl (for just the element).
+    pub(super) debug: unsafe fn(&T, &mut Formatter) -> fmt::Result,
+    /// The `PartialEq` impl (for just the element). If this is `None`,
+    /// field-wise equality checks (via `FieldVtable`) should be performed.
+    pub(super) eq: Option<unsafe fn(&T, &T) -> bool>,
+    /// The `Repr` impl (for just the element). If this is `None`, a generic
+    /// name + fields representation should be produced.
+    pub(super) repr: Option<unsafe fn(&T) -> EcoString>,
+
+    /// Produces a reference to a `static` variable holding a `LazyElementStore`
+    /// that is unique for this element and can be populated with data that is
+    /// somewhat costly to initialize at runtime and shouldn't be initialized
+    /// over and over again. Must be a function rather than a direct reference
+    /// so that we can store the vtable in a `const` without Rust complaining
+    /// about the presence of interior mutability.
+    pub(super) store: fn() -> &'static LazyElementStore,
+}
+
+impl ContentVtable {
+    /// Creates the vtable for an element.
+    pub const fn new<E: NativeElement>(
+        name: &'static str,
+        title: &'static str,
+        docs: &'static str,
+        fields: &'static [FieldVtable<Packed<E>>],
+        field_id: fn(name: &str) -> Option<u8>,
+        capability: fn(TypeId) -> Option<NonNull<()>>,
+        store: fn() -> &'static LazyElementStore,
+    ) -> ContentVtable<Packed<E>> {
+        ContentVtable {
+            name,
+            title,
+            docs,
+            keywords: &[],
+            fields,
+            field_id,
+            construct: <E as Construct>::construct,
+            set: <E as Set>::set,
+            local_name: None,
+            scope: || Scope::new(),
+            capability,
+            drop: RawContent::drop_impl::<E>,
+            clone: RawContent::clone_impl::<E>,
+            hash: |elem| typst_utils::hash128(elem.as_ref()),
+            debug: |elem, f| Debug::fmt(elem.as_ref(), f),
+            eq: None,
+            repr: None,
+            store,
+        }
+    }
+
+    /// Retrieves the vtable of the element with the given ID.
+    pub fn field(&self, id: u8) -> Option<&'static FieldVtable> {
+        self.fields.get(usize::from(id))
+    }
+}
+
+impl<E: NativeElement> ContentVtable<Packed<E>> {
+    /// Attaches search keywords for the documentation.
+    pub const fn with_keywords(mut self, keywords: &'static [&'static str]) -> Self {
+        self.keywords = keywords;
+        self
+    }
+
+    /// Takes a [`Repr`] impl into account.
+    pub const fn with_repr(mut self) -> Self
+    where
+        E: Repr,
+    {
+        self.repr = Some(|e| E::repr(&**e));
+        self
+    }
+
+    /// Takes a [`PartialEq`] impl into account.
+    pub const fn with_partial_eq(mut self) -> Self
+    where
+        E: PartialEq,
+    {
+        self.eq = Some(|a, b| E::eq(&**a, &**b));
+        self
+    }
+
+    /// Takes a [`LocalName`] impl into account.
+    pub const fn with_local_name(mut self) -> Self
+    where
+        Packed<E>: LocalName,
+    {
+        self.local_name = Some(<Packed<E> as LocalName>::local_name);
+        self
+    }
+
+    /// Takes a [`NativeScope`] impl into account.
+    pub const fn with_scope(mut self) -> Self
+    where
+        E: NativeScope,
+    {
+        self.scope = || E::scope();
+        self
+    }
+
+    /// Type-erases the data.
+    pub const fn erase(self) -> ContentVtable {
+        // Safety:
+        // - `ContentVtable` is `repr(C)`.
+        // - `ContentVtable` does not hold any `E`-specific data except for
+        //   function pointers.
+        // - All functions pointers have the same memory layout.
+        // - All functions containing `E` are marked as unsafe and callers need
+        //   to uphold the guarantee that they only call them with raw content
+        //   that is of type `E`.
+        // - `Packed<E>` and `RawContent` have the exact same memory layout
+        //   because of `repr(transparent)`.
+        unsafe {
+            std::mem::transmute::<ContentVtable<Packed<E>>, ContentVtable<RawContent>>(
+                self,
+            )
+        }
+    }
+}
+
+impl<T> ContentHandle<T> {
+    /// Provides safe access to operations for the field with the given `id`.
+    pub(super) fn field(self, id: u8) -> Option<FieldHandle<T>> {
+        self.fields.get(usize::from(id)).map(|vtable| {
+            // Safety: Field vtables are of same type as the content vtable.
+            unsafe { Handle::new(self.0, vtable) }
+        })
+    }
+
+    /// Provides safe access to all field operations.
+    pub(super) fn fields(self) -> impl Iterator<Item = FieldHandle<T>>
+    where
+        T: Copy,
+    {
+        self.fields.iter().map(move |vtable| {
+            // Safety: Field vtables are of same type as the content vtable.
+            unsafe { Handle::new(self.0, vtable) }
+        })
+    }
+}
+
+impl ContentHandle<&RawContent> {
+    /// See [`ContentVtable::debug`].
+    pub fn debug(&self, f: &mut Formatter) -> fmt::Result {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        unsafe { (self.1.debug)(self.0, f) }
+    }
+
+    /// See [`ContentVtable::repr`].
+    pub fn repr(&self) -> Option<EcoString> {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        unsafe { self.1.repr.map(|f| f(self.0)) }
+    }
+
+    /// See [`ContentVtable::clone`].
+    pub fn clone(&self) -> RawContent {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        unsafe { (self.1.clone)(self.0) }
+    }
+
+    /// See [`ContentVtable::hash`].
+    pub fn hash(&self) -> u128 {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        unsafe { (self.1.hash)(self.0) }
+    }
+}
+
+impl ContentHandle<&mut RawContent> {
+    /// See [`ContentVtable::drop`].
+    pub unsafe fn drop(&mut self) {
+        // Safety:
+        // - `Handle` has the invariant that the vtable is matching.
+        // - The caller satifies the requirements of `drop`
+        unsafe { (self.1.drop)(self.0) }
+    }
+}
+
+impl ContentHandle<(&RawContent, &RawContent)> {
+    /// See [`ContentVtable::eq`].
+    pub fn eq(&self) -> Option<bool> {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        let (a, b) = self.0;
+        unsafe { self.1.eq.map(|f| f(a, b)) }
+    }
+}
+
+/// A vtable for performing field-specific actions on type-erased
+/// content. Also contains general metadata for the specific field.
+#[repr(C)]
+pub struct FieldVtable<T: 'static = RawContent> {
+    /// The field's name, as in code.
+    pub(super) name: &'static str,
+    /// The fields's documentation (as Markdown).
+    pub(super) docs: &'static str,
+
+    /// Whether the field's parameter is positional.
+    pub(super) positional: bool,
+    /// Whether the field's parameter is variadic.
+    pub(super) variadic: bool,
+    /// Whether the field's parameter is required.
+    pub(super) required: bool,
+    /// Whether the field can be set via a set rule.
+    pub(super) settable: bool,
+    /// Whether the field is synthesized (i.e. initially not present).
+    pub(super) synthesized: bool,
+    /// Reflects what types the field's parameter accepts.
+    pub(super) input: fn() -> CastInfo,
+    /// Produces the default value of the field, if any. This would e.g. be
+    /// `None` for a required parameter.
+    pub(super) default: Option<fn() -> Value>,
+
+    /// Whether the field is set on the given element. Always true for required
+    /// fields, but can be false for settable or synthesized fields.
+    pub(super) has: unsafe fn(elem: &T) -> bool,
+    /// Retrieves the field and [turns it into a
+    /// value](crate::foundations::IntoValue).
+    pub(super) get: unsafe fn(elem: &T) -> Option<Value>,
+    /// Retrieves the field given styles. The resulting value may come from the
+    /// element, the style chain, or a mix (if it's a
+    /// [`Fold`](crate::foundations::Fold) field).
+    pub(super) get_with_styles: unsafe fn(elem: &T, StyleChain) -> Option<Value>,
+    /// Retrieves the field just from the styles.
+    pub(super) get_from_styles: fn(StyleChain) -> Option<Value>,
+    /// Sets the field from the styles if it is currently unset. (Or merges
+    /// with the style data in case of a `Fold` field).
+    pub(super) materialize: unsafe fn(elem: &mut T, styles: StyleChain),
+    /// Compares the field for equality.
+    pub(super) eq: unsafe fn(a: &T, b: &T) -> bool,
+}
+
+impl FieldHandle<&RawContent> {
+    /// See [`FieldVtable::has`].
+    pub fn has(&self) -> bool {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        unsafe { (self.1.has)(self.0) }
+    }
+
+    /// See [`FieldVtable::get`].
+    pub fn get(&self) -> Option<Value> {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        unsafe { (self.1.get)(self.0) }
+    }
+
+    /// See [`FieldVtable::get_with_styles`].
+    pub fn get_with_styles(&self, styles: StyleChain) -> Option<Value> {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        unsafe { (self.1.get_with_styles)(self.0, styles) }
+    }
+}
+
+impl FieldHandle<&mut RawContent> {
+    /// See [`FieldVtable::materialize`].
+    pub fn materialize(&mut self, styles: StyleChain) {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        unsafe { (self.1.materialize)(self.0, styles) }
+    }
+}
+
+impl FieldHandle<(&RawContent, &RawContent)> {
+    /// See [`FieldVtable::eq`].
+    pub fn eq(&self) -> bool {
+        // Safety: `Handle` has the invariant that the vtable is matching.
+        let (a, b) = self.0;
+        unsafe { (self.1.eq)(a, b) }
+    }
+}

crates/typst-library/src/foundations/context.rs

@@ -3,7 +3,7 @@ use comemo::Track;
 use crate::diag::{bail, Hint, HintedStrResult, SourceResult};
 use crate::engine::Engine;
 use crate::foundations::{
-    elem, Args, Construct, Content, Func, Packed, Show, StyleChain, Value,
+    elem, Args, Construct, Content, Func, ShowFn, StyleChain, Value,
 };
 use crate::introspection::{Locatable, Location};
 
@@ -61,7 +61,7 @@ fn require<T>(val: Option<T>) -> HintedStrResult<T> {
 }
 
 /// Executes a `context` block.
-#[elem(Construct, Locatable, Show)]
+#[elem(Construct, Locatable)]
 pub struct ContextElem {
     /// The function to call with the context.
     #[required]
@@ -75,11 +75,8 @@ impl Construct for ContextElem {
     }
 }
 
-impl Show for Packed<ContextElem> {
-    #[typst_macros::time(name = "context", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let loc = self.location().unwrap();
-        let context = Context::new(Some(loc), Some(styles));
-        Ok(self.func.call::<[Value; 0]>(engine, context.track(), [])?.display())
-    }
-}
+pub const CONTEXT_RULE: ShowFn<ContextElem> = |elem, engine, styles| {
+    let loc = elem.location().unwrap();
+    let context = Context::new(Some(loc), Some(styles));
+    Ok(elem.func.call::<[Value; 0]>(engine, context.track(), [])?.display())
+};

crates/typst-library/src/foundations/mod.rs

@@ -17,7 +17,6 @@ mod datetime;
 mod decimal;
 mod dict;
 mod duration;
-mod element;
 mod fields;
 mod float;
 mod func;
@@ -49,7 +48,6 @@ pub use self::datetime::*;
 pub use self::decimal::*;
 pub use self::dict::*;
 pub use self::duration::*;
-pub use self::element::*;
 pub use self::fields::*;
 pub use self::float::*;
 pub use self::func::*;

crates/typst-library/src/foundations/scope.rs

@@ -8,8 +8,7 @@ use typst_syntax::Span;
 
 use crate::diag::{bail, DeprecationSink, HintedStrResult, HintedString, StrResult};
 use crate::foundations::{
-    Element, Func, IntoValue, NativeElement, NativeFunc, NativeFuncData, NativeType,
-    Type, Value,
+    Func, IntoValue, NativeElement, NativeFunc, NativeFuncData, NativeType, Value,
 };
 use crate::{Category, Library};
 
@@ -149,15 +148,15 @@ impl Scope {
     /// Define a native type.
     #[track_caller]
     pub fn define_type<T: NativeType>(&mut self) -> &mut Binding {
-        let data = T::data();
-        self.define(data.name, Type::from(data))
+        let ty = T::ty();
+        self.define(ty.short_name(), ty)
     }
 
     /// Define a native element.
     #[track_caller]
     pub fn define_elem<T: NativeElement>(&mut self) -> &mut Binding {
-        let data = T::data();
-        self.define(data.name, Element::from(data))
+        let elem = T::ELEM;
+        self.define(elem.name(), elem)
     }
 
     /// Define a built-in with compile-time known name and returns a mutable

crates/typst-library/src/foundations/selector.rs

@@ -21,12 +21,12 @@ macro_rules! __select_where {
         let mut fields = ::smallvec::SmallVec::new();
         $(
             fields.push((
-                <$ty as $crate::foundations::Fields>::Enum::$field as u8,
+                <$ty>::$field.index(),
                 $crate::foundations::IntoValue::into_value($value),
             ));
         )*
         $crate::foundations::Selector::Elem(
-            <$ty as $crate::foundations::NativeElement>::elem(),
+            <$ty as $crate::foundations::NativeElement>::ELEM,
             Some(fields),
         )
     }};

crates/typst-library/src/foundations/str.rs

@@ -179,24 +179,40 @@ impl Str {
     }
 
     /// Extracts the first grapheme cluster of the string.
-    /// Fails with an error if the string is empty.
+    ///
+    /// Returns the provided default value if the string is empty or fails with
+    /// an error if no default value was specified.
     #[func]
-    pub fn first(&self) -> StrResult<Str> {
+    pub fn first(
+        &self,
+        /// A default value to return if the string is empty.
+        #[named]
+        default: Option<Str>,
+    ) -> StrResult<Str> {
         self.0
             .graphemes(true)
             .next()
             .map(Into::into)
+            .or(default)
             .ok_or_else(string_is_empty)
     }
 
     /// Extracts the last grapheme cluster of the string.
-    /// Fails with an error if the string is empty.
+    ///
+    /// Returns the provided default value if the string is empty or fails with
+    /// an error if no default value was specified.
     #[func]
-    pub fn last(&self) -> StrResult<Str> {
+    pub fn last(
+        &self,
+        /// A default value to return if the string is empty.
+        #[named]
+        default: Option<Str>,
+    ) -> StrResult<Str> {
         self.0
             .graphemes(true)
             .next_back()
             .map(Into::into)
+            .or(default)
             .ok_or_else(string_is_empty)
     }
 

crates/typst-library/src/foundations/styles.rs

@@ -1,4 +1,5 @@
 use std::any::{Any, TypeId};
+use std::collections::HashMap;
 use std::fmt::{self, Debug, Formatter};
 use std::hash::{Hash, Hasher};
 use std::{mem, ptr};
@@ -12,8 +13,8 @@ use typst_utils::LazyHash;
 use crate::diag::{SourceResult, Trace, Tracepoint};
 use crate::engine::Engine;
 use crate::foundations::{
-    cast, ty, Content, Context, Element, Func, NativeElement, OneOrMultiple, Repr,
-    Selector,
+    cast, ty, Content, Context, Element, Field, Func, NativeElement, OneOrMultiple,
+    Packed, RefableProperty, Repr, Selector, SettableProperty, Target,
 };
 use crate::text::{FontFamily, FontList, TextElem};
 
@@ -48,7 +49,16 @@ impl Styles {
     /// If the property needs folding and the value is already contained in the
     /// style map, `self` contributes the outer values and `value` is the inner
     /// one.
-    pub fn set(&mut self, style: impl Into<Style>) {
+    pub fn set<E, const I: u8>(&mut self, field: Field<E, I>, value: E::Type)
+    where
+        E: SettableProperty<I>,
+        E::Type: Debug + Clone + Hash + Send + Sync + 'static,
+    {
+        self.push(Property::new(field, value));
+    }
+
+    /// Add a new style to the list.
+    pub fn push(&mut self, style: impl Into<Style>) {
         self.0.push(LazyHash::new(style.into()));
     }
 
@@ -101,22 +111,25 @@ impl Styles {
     }
 
     /// Whether there is a style for the given field of the given element.
-    pub fn has<T: NativeElement>(&self, field: u8) -> bool {
-        let elem = T::elem();
+    pub fn has<E: NativeElement, const I: u8>(&self, _: Field<E, I>) -> bool {
+        let elem = E::ELEM;
         self.0
             .iter()
             .filter_map(|style| style.property())
-            .any(|property| property.is_of(elem) && property.id == field)
+            .any(|property| property.is_of(elem) && property.id == I)
     }
 
     /// Set a font family composed of a preferred family and existing families
     /// from a style chain.
     pub fn set_family(&mut self, preferred: FontFamily, existing: StyleChain) {
-        self.set(TextElem::set_font(FontList(
-            std::iter::once(preferred)
-                .chain(TextElem::font_in(existing).into_iter().cloned())
-                .collect(),
-        )));
+        self.set(
+            TextElem::font,
+            FontList(
+                std::iter::once(preferred)
+                    .chain(existing.get_ref(TextElem::font).into_iter().cloned())
+                    .collect(),
+            ),
+        );
     }
 }
 
@@ -281,14 +294,14 @@ pub struct Property {
 
 impl Property {
     /// Create a new property from a key-value pair.
-    pub fn new<E, T>(id: u8, value: T) -> Self
+    pub fn new<E, const I: u8>(_: Field<E, I>, value: E::Type) -> Self
     where
-        E: NativeElement,
-        T: Debug + Clone + Hash + Send + Sync + 'static,
+        E: SettableProperty<I>,
+        E::Type: Debug + Clone + Hash + Send + Sync + 'static,
     {
         Self {
-            elem: E::elem(),
-            id,
+            elem: E::ELEM,
+            id: I,
             value: Block::new(value),
             span: Span::detached(),
             liftable: false,
@@ -340,8 +353,11 @@ impl Block {
     }
 
     /// Downcasts the block to the specified type.
-    fn downcast<T: 'static>(&self) -> Option<&T> {
-        self.0.as_any().downcast_ref()
+    fn downcast<T: 'static>(&self, func: Element, id: u8) -> &T {
+        self.0
+            .as_any()
+            .downcast_ref()
+            .unwrap_or_else(|| block_wrong_type(func, id, self))
     }
 }
 
@@ -528,6 +544,103 @@ impl<'a> StyleChain<'a> {
         Self { head: &root.0, tail: None }
     }
 
+    /// Retrieves the value of the given field from the style chain.
+    ///
+    /// A `Field` value is a zero-sized value that specifies which field of an
+    /// element you want to retrieve on the type-system level. It also ensures
+    /// that Rust can infer the correct return type.
+    ///
+    /// Should be preferred over [`get_cloned`](Self::get_cloned) or
+    /// [`get_ref`](Self::get_ref), but is only available for [`Copy`] types.
+    /// For other types an explicit decision needs to be made whether cloning is
+    /// necessary.
+    pub fn get<E, const I: u8>(self, field: Field<E, I>) -> E::Type
+    where
+        E: SettableProperty<I>,
+        E::Type: Copy,
+    {
+        self.get_cloned(field)
+    }
+
+    /// Retrieves and clones the value from the style chain.
+    ///
+    /// Prefer [`get`](Self::get) if the type is `Copy` and
+    /// [`get_ref`](Self::get_ref) if a reference suffices.
+    pub fn get_cloned<E, const I: u8>(self, _: Field<E, I>) -> E::Type
+    where
+        E: SettableProperty<I>,
+    {
+        if let Some(fold) = E::FOLD {
+            self.get_folded::<E::Type>(E::ELEM, I, fold, E::default())
+        } else {
+            self.get_unfolded::<E::Type>(E::ELEM, I)
+                .cloned()
+                .unwrap_or_else(E::default)
+        }
+    }
+
+    /// Retrieves a reference to the value of the given field from the style
+    /// chain.
+    ///
+    /// Not possible if the value needs folding.
+    pub fn get_ref<E, const I: u8>(self, _: Field<E, I>) -> &'a E::Type
+    where
+        E: RefableProperty<I>,
+    {
+        self.get_unfolded(E::ELEM, I).unwrap_or_else(|| E::default_ref())
+    }
+
+    /// Retrieves the value and then immediately [resolves](Resolve) it.
+    pub fn resolve<E, const I: u8>(
+        self,
+        field: Field<E, I>,
+    ) -> <E::Type as Resolve>::Output
+    where
+        E: SettableProperty<I>,
+        E::Type: Resolve,
+    {
+        self.get_cloned(field).resolve(self)
+    }
+
+    /// Retrieves a reference to a field, also taking into account the
+    /// instance's value if any.
+    fn get_unfolded<T: 'static>(self, func: Element, id: u8) -> Option<&'a T> {
+        self.find(func, id).map(|block| block.downcast(func, id))
+    }
+
+    /// Retrieves a reference to a field, also taking into account the
+    /// instance's value if any.
+    fn get_folded<T: 'static + Clone>(
+        self,
+        func: Element,
+        id: u8,
+        fold: fn(T, T) -> T,
+        default: T,
+    ) -> T {
+        let iter = self
+            .properties(func, id)
+            .map(|block| block.downcast::<T>(func, id).clone());
+
+        if let Some(folded) = iter.reduce(fold) {
+            fold(folded, default)
+        } else {
+            default
+        }
+    }
+
+    /// Iterate over all values for the given property in the chain.
+    fn find(self, func: Element, id: u8) -> Option<&'a Block> {
+        self.properties(func, id).next()
+    }
+
+    /// Iterate over all values for the given property in the chain.
+    fn properties(self, func: Element, id: u8) -> impl Iterator<Item = &'a Block> {
+        self.entries()
+            .filter_map(|style| style.property())
+            .filter(move |property| property.is(func, id))
+            .map(|property| &property.value)
+    }
+
     /// Make the given chainable the first link of this chain.
     ///
     /// The resulting style chain contains styles from `local` as well as
@@ -540,80 +653,6 @@ impl<'a> StyleChain<'a> {
         Chainable::chain(local, self)
     }
 
-    /// Cast the first value for the given property in the chain.
-    pub fn get<T: Clone + 'static>(
-        self,
-        func: Element,
-        id: u8,
-        inherent: Option<&T>,
-        default: impl Fn() -> T,
-    ) -> T {
-        self.properties::<T>(func, id, inherent)
-            .next()
-            .cloned()
-            .unwrap_or_else(default)
-    }
-
-    /// Cast the first value for the given property in the chain,
-    /// returning a borrowed value.
-    pub fn get_ref<T: 'static>(
-        self,
-        func: Element,
-        id: u8,
-        inherent: Option<&'a T>,
-        default: impl Fn() -> &'a T,
-    ) -> &'a T {
-        self.properties::<T>(func, id, inherent)
-            .next()
-            .unwrap_or_else(default)
-    }
-
-    /// Cast the first value for the given property in the chain, taking
-    /// `Fold` implementations into account.
-    pub fn get_folded<T: Fold + Clone + 'static>(
-        self,
-        func: Element,
-        id: u8,
-        inherent: Option<&T>,
-        default: impl Fn() -> T,
-    ) -> T {
-        fn next<T: Fold>(
-            mut values: impl Iterator<Item = T>,
-            default: &impl Fn() -> T,
-        ) -> T {
-            values
-                .next()
-                .map(|value| value.fold(next(values, default)))
-                .unwrap_or_else(default)
-        }
-        next(self.properties::<T>(func, id, inherent).cloned(), &default)
-    }
-
-    /// Iterate over all values for the given property in the chain.
-    fn properties<T: 'static>(
-        self,
-        func: Element,
-        id: u8,
-        inherent: Option<&'a T>,
-    ) -> impl Iterator<Item = &'a T> {
-        inherent.into_iter().chain(
-            self.entries()
-                .filter_map(|style| style.property())
-                .filter(move |property| property.is(func, id))
-                .map(|property| &property.value)
-                .map(move |value| {
-                    value.downcast().unwrap_or_else(|| {
-                        panic!(
-                            "attempted to read a value of a different type than was written {}.{}: {:?}",
-                            func.name(),
-                            func.field_name(id).unwrap(),
-                            value
-                        )
-                    })
-                }),
-        )
-    }
-
     /// Iterate over the entries of the chain.
     pub fn entries(self) -> Entries<'a> {
         Entries { inner: [].as_slice().iter(), links: self.links() }
@@ -804,6 +843,9 @@ impl<T: Resolve> Resolve for Option<T> {
 /// #set rect(stroke: 4pt)
 /// #rect()
 /// ```
+///
+/// Note: Folding must be associative, i.e. any implementation must satisfy
+/// `fold(fold(a, b), c) == fold(a, fold(b, c))`.
 pub trait Fold {
     /// Fold this inner value with an outer folded value.
     fn fold(self, outer: Self) -> Self;
@@ -847,6 +889,9 @@ impl<T> Fold for OneOrMultiple<T> {
     }
 }
 
+/// A [folding](Fold) function.
+pub type FoldFn<T> = fn(T, T) -> T;
+
 /// A variant of fold for foldable optional (`Option<T>`) values where an inner
 /// `None` value isn't respected (contrary to `Option`'s usual `Fold`
 /// implementation, with which folding with an inner `None` always returns
@@ -884,3 +929,139 @@ impl Fold for Depth {
         Self(outer.0 + self.0)
     }
 }
+
+#[cold]
+fn block_wrong_type(func: Element, id: u8, value: &Block) -> ! {
+    panic!(
+        "attempted to read a value of a different type than was written {}.{}: {:?}",
+        func.name(),
+        func.field_name(id).unwrap(),
+        value
+    )
+}
+
+/// Holds native show rules.
+pub struct NativeRuleMap {
+    rules: HashMap<(Element, Target), NativeShowRule>,
+}
+
+/// The signature of a native show rule.
+pub type ShowFn<T> = fn(
+    elem: &Packed<T>,
+    engine: &mut Engine,
+    styles: StyleChain,
+) -> SourceResult<Content>;
+
+impl NativeRuleMap {
+    /// Creates a new rule map.
+    ///
+    /// Should be populated with rules for all target-element combinations that
+    /// are supported.
+    ///
+    /// Contains built-in rules for a few special elements.
+    pub fn new() -> Self {
+        let mut rules = Self { rules: HashMap::new() };
+
+        // ContextElem is as special as SequenceElem and StyledElem and could,
+        // in theory, also be special cased in realization.
+        rules.register_builtin(crate::foundations::CONTEXT_RULE);
+
+        // CounterDisplayElem only exists because the compiler can't currently
+        // express the equivalent of `context counter(..).display(..)` in native
+        // code (no native closures).
+        rules.register_builtin(crate::introspection::COUNTER_DISPLAY_RULE);
+
+        // These are all only for introspection and empty on all targets.
+        rules.register_empty::<crate::introspection::CounterUpdateElem>();
+        rules.register_empty::<crate::introspection::StateUpdateElem>();
+        rules.register_empty::<crate::introspection::MetadataElem>();
+        rules.register_empty::<crate::model::PrefixInfo>();
+
+        rules
+    }
+
+    /// Registers a rule for all targets.
+    fn register_empty<T: NativeElement>(&mut self) {
+        self.register_builtin::<T>(|_, _, _| Ok(Content::empty()));
+    }
+
+    /// Registers a rule for all targets.
+    fn register_builtin<T: NativeElement>(&mut self, f: ShowFn<T>) {
+        self.register(Target::Paged, f);
+        self.register(Target::Html, f);
+    }
+
+    /// Registers a rule for a target.
+    ///
+    /// Panics if a rule already exists for this target-element combination.
+    pub fn register<T: NativeElement>(&mut self, target: Target, f: ShowFn<T>) {
+        let res = self.rules.insert((T::ELEM, target), NativeShowRule::new(f));
+        if res.is_some() {
+            panic!(
+                "duplicate native show rule for `{}` on {target:?} target",
+                T::ELEM.name()
+            )
+        }
+    }
+
+    /// Retrieves the rule that applies to the `content` on the current
+    /// `target`.
+    pub fn get(&self, target: Target, content: &Content) -> Option<NativeShowRule> {
+        self.rules.get(&(content.func(), target)).copied()
+    }
+}
+
+impl Default for NativeRuleMap {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+pub use rule::NativeShowRule;
+
+mod rule {
+    use super::*;
+
+    /// The show rule for a native element.
+    #[derive(Copy, Clone)]
+    pub struct NativeShowRule {
+        /// The element to which this rule applies.
+        elem: Element,
+        /// Must only be called with content of the appropriate type.
+        f: unsafe fn(
+            elem: &Content,
+            engine: &mut Engine,
+            styles: StyleChain,
+        ) -> SourceResult<Content>,
+    }
+
+    impl NativeShowRule {
+        /// Create a new type-erased show rule.
+        pub fn new<T: NativeElement>(f: ShowFn<T>) -> Self {
+            Self {
+                elem: T::ELEM,
+                // Safety: The two function pointer types only differ in the
+                // first argument, which changes from `&Packed<T>` to
+                // `&Content`. `Packed<T>` is a transparent wrapper around
+                // `Content`. The resulting function is unsafe to call because
+                // content of the correct type must be passed to it.
+                #[allow(clippy::missing_transmute_annotations)]
+                f: unsafe { std::mem::transmute(f) },
+            }
+        }
+
+        /// Applies the rule to content. Panics if the content is of the wrong
+        /// type.
+        pub fn apply(
+            &self,
+            content: &Content,
+            engine: &mut Engine,
+            styles: StyleChain,
+        ) -> SourceResult<Content> {
+            assert_eq!(content.elem(), self.elem);
+
+            // Safety: We just checked that the element is of the correct type.
+            unsafe { (self.f)(content, engine, styles) }
+        }
+    }
+}

crates/typst-library/src/foundations/target.rs

@@ -4,7 +4,7 @@ use crate::diag::HintedStrResult;
 use crate::foundations::{elem, func, Cast, Context};
 
 /// The export target.
-#[derive(Debug, Default, Copy, Clone, PartialEq, Hash, Cast)]
+#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash, Cast)]
 pub enum Target {
     /// The target that is used for paged, fully laid-out content.
     #[default]
@@ -73,5 +73,5 @@ pub struct TargetElem {
 /// ```
 #[func(contextual)]
 pub fn target(context: Tracked<Context>) -> HintedStrResult<Target> {
-    Ok(TargetElem::target_in(context.styles()?))
+    Ok(context.styles()?.get(TargetElem::target))
 }

crates/typst-library/src/html/mod.rs

@@ -1,23 +1,12 @@
 //! HTML output.
 
 mod dom;
-mod typed;
 
 pub use self::dom::*;
 
 use ecow::EcoString;
 
-use crate::foundations::{elem, Content, Module, Scope};
-
-/// Create a module with all HTML definitions.
-pub fn module() -> Module {
-    let mut html = Scope::deduplicating();
-    html.start_category(crate::Category::Html);
-    html.define_elem::<HtmlElem>();
-    html.define_elem::<FrameElem>();
-    self::typed::define(&mut html);
-    Module::new("html", html)
-}
+use crate::foundations::{elem, Content};
 
 /// An HTML element that can contain Typst content.
 ///
@@ -47,21 +36,22 @@ pub struct HtmlElem {
     pub tag: HtmlTag,
 
     /// The element's HTML attributes.
-    #[borrowed]
     pub attrs: HtmlAttrs,
 
     /// The contents of the HTML element.
     ///
     /// The body can be arbitrary Typst content.
     #[positional]
-    #[borrowed]
     pub body: Option<Content>,
 }
 
 impl HtmlElem {
     /// Add an attribute to the element.
     pub fn with_attr(mut self, attr: HtmlAttr, value: impl Into<EcoString>) -> Self {
-        self.attrs.get_or_insert_with(Default::default).push(attr, value);
+        self.attrs
+            .as_option_mut()
+            .get_or_insert_with(Default::default)
+            .push(attr, value);
         self
     }
 }

crates/typst-library/src/introspection/counter.rs

@@ -12,7 +12,7 @@ use crate::engine::{Engine, Route, Sink, Traced};
 use crate::foundations::{
     cast, elem, func, scope, select_where, ty, Args, Array, Construct, Content, Context,
     Element, Func, IntoValue, Label, LocatableSelector, NativeElement, Packed, Repr,
-    Selector, Show, Smart, Str, StyleChain, Value,
+    Selector, ShowFn, Smart, Str, StyleChain, Value,
 };
 use crate::introspection::{Introspector, Locatable, Location, Tag};
 use crate::layout::{Frame, FrameItem, PageElem};
@@ -338,7 +338,7 @@ impl Counter {
 
     /// The selector relevant for this counter's updates.
     fn selector(&self) -> Selector {
-        let mut selector = select_where!(CounterUpdateElem, Key => self.0.clone());
+        let mut selector = select_where!(CounterUpdateElem, key => self.0.clone());
 
         if let CounterKey::Selector(key) = &self.0 {
             selector = Selector::Or(eco_vec![selector, key.clone()]);
@@ -367,16 +367,16 @@ impl Counter {
             .or_else(|| {
                 let styles = styles?;
                 match self.0 {
-                    CounterKey::Page => PageElem::numbering_in(styles).clone(),
+                    CounterKey::Page => styles.get_cloned(PageElem::numbering),
                     CounterKey::Selector(Selector::Elem(func, _)) => {
-                        if func == HeadingElem::elem() {
-                            HeadingElem::numbering_in(styles).clone()
-                        } else if func == FigureElem::elem() {
-                            FigureElem::numbering_in(styles).clone()
-                        } else if func == EquationElem::elem() {
-                            EquationElem::numbering_in(styles).clone()
-                        } else if func == FootnoteElem::elem() {
-                            Some(FootnoteElem::numbering_in(styles).clone())
+                        if func == HeadingElem::ELEM {
+                            styles.get_cloned(HeadingElem::numbering)
+                        } else if func == FigureElem::ELEM {
+                            styles.get_cloned(FigureElem::numbering)
+                        } else if func == EquationElem::ELEM {
+                            styles.get_cloned(EquationElem::numbering)
+                        } else if func == FootnoteElem::ELEM {
+                            Some(styles.get_cloned(FootnoteElem::numbering))
                         } else {
                             None
                         }
@@ -398,7 +398,7 @@ impl Counter {
 
     /// Selects all state updates.
     pub fn select_any() -> Selector {
-        CounterUpdateElem::elem().select()
+        CounterUpdateElem::ELEM.select()
     }
 }
 
@@ -565,14 +565,14 @@ pub enum CounterKey {
 cast! {
     CounterKey,
     self => match self {
-        Self::Page => PageElem::elem().into_value(),
+        Self::Page => PageElem::ELEM.into_value(),
         Self::Selector(v) => v.into_value(),
         Self::Str(v) => v.into_value(),
     },
     v: Str => Self::Str(v),
     v: Label => Self::Selector(Selector::Label(v)),
     v: Element => {
-        if v == PageElem::elem() {
+        if v == PageElem::ELEM {
             Self::Page
         } else {
             Self::Selector(LocatableSelector::from_value(v.into_value())?.0)
@@ -683,8 +683,8 @@ cast! {
 }
 
 /// Executes an update of a counter.
-#[elem(Construct, Locatable, Show, Count)]
-struct CounterUpdateElem {
+#[elem(Construct, Locatable, Count)]
+pub struct CounterUpdateElem {
     /// The key that identifies the counter.
     #[required]
     key: CounterKey,
@@ -701,12 +701,6 @@ impl Construct for CounterUpdateElem {
     }
 }
 
-impl Show for Packed<CounterUpdateElem> {
-    fn show(&self, _: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(Content::empty())
-    }
-}
-
 impl Count for Packed<CounterUpdateElem> {
     fn update(&self) -> Option<CounterUpdate> {
         Some(self.update.clone())
@@ -714,7 +708,7 @@ impl Count for Packed<CounterUpdateElem> {
 }
 
 /// Executes a display of a counter.
-#[elem(Construct, Locatable, Show)]
+#[elem(Construct, Locatable)]
 pub struct CounterDisplayElem {
     /// The counter.
     #[required]
@@ -738,20 +732,18 @@ impl Construct for CounterDisplayElem {
     }
 }
 
-impl Show for Packed<CounterDisplayElem> {
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        Ok(self
-            .counter
-            .display_impl(
-                engine,
-                self.location().unwrap(),
-                self.numbering.clone(),
-                self.both,
-                Some(styles),
-            )?
-            .display())
-    }
-}
+pub const COUNTER_DISPLAY_RULE: ShowFn<CounterDisplayElem> = |elem, engine, styles| {
+    Ok(elem
+        .counter
+        .display_impl(
+            engine,
+            elem.location().unwrap(),
+            elem.numbering.clone(),
+            elem.both,
+            Some(styles),
+        )?
+        .display())
+};
 
 /// An specialized handler of the page counter that tracks both the physical
 /// and the logical page counter.

crates/typst-library/src/introspection/metadata.rs

@@ -1,6 +1,4 @@
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{elem, Content, Packed, Show, StyleChain, Value};
+use crate::foundations::{elem, Value};
 use crate::introspection::Locatable;
 
 /// Exposes a value to the query system without producing visible content.
@@ -24,15 +22,9 @@ use crate::introspection::Locatable;
 ///   query(<note>).first().value
 /// }
 /// ```
-#[elem(Show, Locatable)]
+#[elem(Locatable)]
 pub struct MetadataElem {
     /// The value to embed into the document.
     #[required]
     pub value: Value,
 }
-
-impl Show for Packed<MetadataElem> {
-    fn show(&self, _: &mut Engine, _styles: StyleChain) -> SourceResult<Content> {
-        Ok(Content::empty())
-    }
-}

crates/typst-library/src/introspection/state.rs

@@ -6,8 +6,7 @@ use crate::diag::{bail, At, SourceResult};
 use crate::engine::{Engine, Route, Sink, Traced};
 use crate::foundations::{
     cast, elem, func, scope, select_where, ty, Args, Construct, Content, Context, Func,
-    LocatableSelector, NativeElement, Packed, Repr, Selector, Show, Str, StyleChain,
-    Value,
+    LocatableSelector, NativeElement, Repr, Selector, Str, Value,
 };
 use crate::introspection::{Introspector, Locatable, Location};
 use crate::routines::Routines;
@@ -259,12 +258,12 @@ impl State {
 
     /// The selector for this state's updates.
     fn selector(&self) -> Selector {
-        select_where!(StateUpdateElem, Key => self.key.clone())
+        select_where!(StateUpdateElem, key => self.key.clone())
     }
 
     /// Selects all state updates.
     pub fn select_any() -> Selector {
-        StateUpdateElem::elem().select()
+        StateUpdateElem::ELEM.select()
     }
 }
 
@@ -372,8 +371,8 @@ cast! {
 }
 
 /// Executes a display of a state.
-#[elem(Construct, Locatable, Show)]
-struct StateUpdateElem {
+#[elem(Construct, Locatable)]
+pub struct StateUpdateElem {
     /// The key that identifies the state.
     #[required]
     key: Str,
@@ -389,9 +388,3 @@ impl Construct for StateUpdateElem {
         bail!(args.span, "cannot be constructed manually");
     }
 }
-
-impl Show for Packed<StateUpdateElem> {
-    fn show(&self, _: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(Content::empty())
-    }
-}

crates/typst-library/src/layout/align.rs

@@ -2,11 +2,10 @@ use std::ops::Add;
 
 use ecow::{eco_format, EcoString};
 
-use crate::diag::{bail, HintedStrResult, SourceResult, StrResult};
-use crate::engine::Engine;
+use crate::diag::{bail, HintedStrResult, StrResult};
 use crate::foundations::{
-    cast, elem, func, scope, ty, CastInfo, Content, Fold, FromValue, IntoValue, Packed,
-    Reflect, Repr, Resolve, Show, StyleChain, Value,
+    cast, elem, func, scope, ty, CastInfo, Content, Fold, FromValue, IntoValue, Reflect,
+    Repr, Resolve, StyleChain, Value,
 };
 use crate::layout::{Abs, Axes, Axis, Dir, Side};
 use crate::text::TextElem;
@@ -73,7 +72,7 @@ use crate::text::TextElem;
 /// ```example
 /// Start #h(1fr) End
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct AlignElem {
     /// The [alignment] along both axes.
     ///
@@ -97,13 +96,6 @@ pub struct AlignElem {
     pub body: Content,
 }
 
-impl Show for Packed<AlignElem> {
-    #[typst_macros::time(name = "align", span = self.span())]
-    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        Ok(self.body.clone().aligned(self.alignment(styles)))
-    }
-}
-
 /// Where to align something along an axis.
 ///
 /// Possible values are:
@@ -277,7 +269,7 @@ impl Resolve for Alignment {
     type Output = Axes<FixedAlignment>;
 
     fn resolve(self, styles: StyleChain) -> Self::Output {
-        self.fix(TextElem::dir_in(styles))
+        self.fix(styles.resolve(TextElem::dir))
     }
 }
 
@@ -378,7 +370,7 @@ impl Resolve for HAlignment {
     type Output = FixedAlignment;
 
     fn resolve(self, styles: StyleChain) -> Self::Output {
-        self.fix(TextElem::dir_in(styles))
+        self.fix(styles.resolve(TextElem::dir))
     }
 }
 
@@ -414,7 +406,7 @@ impl Resolve for OuterHAlignment {
     type Output = FixedAlignment;
 
     fn resolve(self, styles: StyleChain) -> Self::Output {
-        self.fix(TextElem::dir_in(styles))
+        self.fix(styles.resolve(TextElem::dir))
     }
 }
 
@@ -636,7 +628,7 @@ where
     type Output = Axes<FixedAlignment>;
 
     fn resolve(self, styles: StyleChain) -> Self::Output {
-        self.fix(TextElem::dir_in(styles))
+        self.fix(styles.resolve(TextElem::dir))
     }
 }
 

crates/typst-library/src/layout/columns.rs

@@ -1,9 +1,7 @@
 use std::num::NonZeroUsize;
 
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{elem, Content, NativeElement, Packed, Show, StyleChain};
-use crate::layout::{BlockElem, Length, Ratio, Rel};
+use crate::foundations::{elem, Content};
+use crate::layout::{Length, Ratio, Rel};
 
 /// Separates a region into multiple equally sized columns.
 ///
@@ -41,7 +39,7 @@ use crate::layout::{BlockElem, Length, Ratio, Rel};
 ///
 /// #lorem(40)
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct ColumnsElem {
     /// The number of columns.
     #[positional]
@@ -49,7 +47,6 @@ pub struct ColumnsElem {
     pub count: NonZeroUsize,
 
     /// The size of the gutter space between each column.
-    #[resolve]
     #[default(Ratio::new(0.04).into())]
     pub gutter: Rel<Length>,
 
@@ -58,14 +55,6 @@ pub struct ColumnsElem {
     pub body: Content,
 }
 
-impl Show for Packed<ColumnsElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::multi_layouter(self.clone(), engine.routines.layout_columns)
-            .pack()
-            .spanned(self.span()))
-    }
-}
-
 /// Forces a column break.
 ///
 /// The function will behave like a [page break]($pagebreak) when used in a

crates/typst-library/src/layout/container.rs

@@ -51,7 +51,6 @@ pub struct BoxElem {
     /// ```example
     /// Image: #box(baseline: 40%, image("tiger.jpg", width: 2cm)).
     /// ```
-    #[resolve]
     pub baseline: Rel<Length>,
 
     /// The box's background color. See the
@@ -60,13 +59,11 @@ pub struct BoxElem {
 
     /// The box's border color. See the
     /// [rectangle's documentation]($rect.stroke) for more details.
-    #[resolve]
     #[fold]
     pub stroke: Sides<Option<Option<Stroke>>>,
 
     /// How much to round the box's corners. See the
     /// [rectangle's documentation]($rect.radius) for more details.
-    #[resolve]
     #[fold]
     pub radius: Corners<Option<Rel<Length>>>,
 
@@ -78,7 +75,6 @@ pub struct BoxElem {
     /// ```example
     /// #rect(inset: 0pt)[Tight]
     /// ```
-    #[resolve]
     #[fold]
     pub inset: Sides<Option<Rel<Length>>>,
 
@@ -97,7 +93,6 @@ pub struct BoxElem {
     ///   radius: 2pt,
     /// )[rectangle].
     /// ```
-    #[resolve]
     #[fold]
     pub outset: Sides<Option<Rel<Length>>>,
 
@@ -119,7 +114,6 @@ pub struct BoxElem {
 
     /// The contents of the box.
     #[positional]
-    #[borrowed]
     pub body: Option<Content>,
 }
 
@@ -262,25 +256,21 @@ pub struct BlockElem {
 
     /// The block's border color. See the
     /// [rectangle's documentation]($rect.stroke) for more details.
-    #[resolve]
     #[fold]
     pub stroke: Sides<Option<Option<Stroke>>>,
 
     /// How much to round the block's corners. See the
     /// [rectangle's documentation]($rect.radius) for more details.
-    #[resolve]
     #[fold]
     pub radius: Corners<Option<Rel<Length>>>,
 
     /// How much to pad the block's content. See the
     /// [box's documentation]($box.inset) for more details.
-    #[resolve]
     #[fold]
     pub inset: Sides<Option<Rel<Length>>>,
 
     /// How much to expand the block's size without affecting the layout. See
     /// the [box's documentation]($box.outset) for more details.
-    #[resolve]
     #[fold]
     pub outset: Sides<Option<Rel<Length>>>,
 
@@ -358,7 +348,6 @@ pub struct BlockElem {
 
     /// The contents of the block.
     #[positional]
-    #[borrowed]
     pub body: Option<BlockBody>,
 }
 

crates/typst-library/src/layout/em.rs

@@ -167,7 +167,7 @@ impl Resolve for Em {
         if self.is_zero() {
             Abs::zero()
         } else {
-            self.at(TextElem::size_in(styles))
+            self.at(styles.resolve(TextElem::size))
         }
     }
 }

crates/typst-library/src/layout/grid/mod.rs

@@ -11,10 +11,10 @@ use crate::diag::{bail, At, HintedStrResult, HintedString, SourceResult};
 use crate::engine::Engine;
 use crate::foundations::{
     cast, elem, scope, Array, CastInfo, Content, Context, Fold, FromValue, Func,
-    IntoValue, NativeElement, Packed, Reflect, Resolve, Show, Smart, StyleChain, Value,
+    IntoValue, Packed, Reflect, Resolve, Smart, StyleChain, Value,
 };
 use crate::layout::{
-    Alignment, BlockElem, Length, OuterHAlignment, OuterVAlignment, Rel, Sides, Sizing,
+    Alignment, Length, OuterHAlignment, OuterVAlignment, Rel, Sides, Sizing,
 };
 use crate::model::{TableCell, TableFooter, TableHLine, TableHeader, TableVLine};
 use crate::visualize::{Paint, Stroke};
@@ -136,7 +136,7 @@ use crate::visualize::{Paint, Stroke};
 ///
 /// Furthermore, strokes of a repeated grid header or footer will take
 /// precedence over regular cell strokes.
-#[elem(scope, Show)]
+#[elem(scope)]
 pub struct GridElem {
     /// The column sizes.
     ///
@@ -144,14 +144,12 @@ pub struct GridElem {
     /// with that many `{auto}`-sized columns. Note that opposed to rows and
     /// gutters, providing a single track size will only ever create a single
     /// column.
-    #[borrowed]
     pub columns: TrackSizings,
 
     /// The row sizes.
     ///
     /// If there are more cells than fit the defined rows, the last row is
     /// repeated until there are no more cells.
-    #[borrowed]
     pub rows: TrackSizings,
 
     /// The gaps between rows and columns.
@@ -169,12 +167,10 @@ pub struct GridElem {
         let gutter = args.named("gutter")?;
         args.named("column-gutter")?.or_else(|| gutter.clone())
     )]
-    #[borrowed]
     pub column_gutter: TrackSizings,
 
     /// The gaps between rows.
     #[parse(args.named("row-gutter")?.or_else(|| gutter.clone()))]
-    #[borrowed]
     pub row_gutter: TrackSizings,
 
     /// How to fill the cells.
@@ -197,7 +193,6 @@ pub struct GridElem {
     ///   [O], [X], [O], [X],
     /// )
     /// ```
-    #[borrowed]
     pub fill: Celled<Option<Paint>>,
 
     /// How to align the cells' content.
@@ -209,7 +204,6 @@ pub struct GridElem {
     ///
     /// You can find an example for this argument at the
     /// [`table.align`]($table.align) parameter.
-    #[borrowed]
     pub align: Celled<Smart<Alignment>>,
 
     /// How to [stroke]($stroke) the cells.
@@ -289,7 +283,6 @@ pub struct GridElem {
     ///   ),
     /// )
     /// ```
-    #[resolve]
     #[fold]
     pub stroke: Celled<Sides<Option<Option<Arc<Stroke>>>>>,
 
@@ -327,14 +320,6 @@ impl GridElem {
     type GridFooter;
 }
 
-impl Show for Packed<GridElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::multi_layouter(self.clone(), engine.routines.layout_grid)
-            .pack()
-            .spanned(self.span()))
-    }
-}
-
 /// Track sizing definitions.
 #[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
 pub struct TrackSizings(pub SmallVec<[Sizing; 4]>);
@@ -541,7 +526,6 @@ pub struct GridHLine {
     ///
     /// Specifying `{none}` removes any lines previously placed across this
     /// line's range, including hlines or per-cell stroke below it.
-    #[resolve]
     #[fold]
     #[default(Some(Arc::new(Stroke::default())))]
     pub stroke: Option<Arc<Stroke>>,
@@ -596,7 +580,6 @@ pub struct GridVLine {
     ///
     /// Specifying `{none}` removes any lines previously placed across this
     /// line's range, including vlines or per-cell stroke below it.
-    #[resolve]
     #[fold]
     #[default(Some(Arc::new(Stroke::default())))]
     pub stroke: Option<Arc<Stroke>>,
@@ -657,7 +640,7 @@ pub struct GridVLine {
 /// which allows you, for example, to apply styles based on a cell's position.
 /// Refer to the examples of the [`table.cell`]($table.cell) element to learn
 /// more about this.
-#[elem(name = "cell", title = "Grid Cell", Show)]
+#[elem(name = "cell", title = "Grid Cell")]
 pub struct GridCell {
     /// The cell's body.
     #[required]
@@ -742,7 +725,6 @@ pub struct GridCell {
     pub inset: Smart<Sides<Option<Rel<Length>>>>,
 
     /// The cell's [stroke]($grid.stroke) override.
-    #[resolve]
     #[fold]
     pub stroke: Sides<Option<Option<Arc<Stroke>>>>,
 
@@ -758,12 +740,6 @@ cast! {
     v: Content => v.into(),
 }
 
-impl Show for Packed<GridCell> {
-    fn show(&self, _engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        show_grid_cell(self.body.clone(), self.inset(styles), self.align(styles))
-    }
-}
-
 impl Default for Packed<GridCell> {
     fn default() -> Self {
         Packed::new(
@@ -784,28 +760,6 @@ impl From<Content> for GridCell {
     }
 }
 
-/// Function with common code to display a grid cell or table cell.
-pub(crate) fn show_grid_cell(
-    mut body: Content,
-    inset: Smart<Sides<Option<Rel<Length>>>>,
-    align: Smart<Alignment>,
-) -> SourceResult<Content> {
-    let inset = inset.unwrap_or_default().map(Option::unwrap_or_default);
-
-    if inset != Sides::default() {
-        // Only pad if some inset is not 0pt.
-        // Avoids a bug where using .padded() in any way inside Show causes
-        // alignment in align(...) to break.
-        body = body.padded(inset);
-    }
-
-    if let Smart::Custom(alignment) = align {
-        body = body.aligned(alignment);
-    }
-
-    Ok(body)
-}
-
 /// A value that can be configured per cell.
 #[derive(Debug, Clone, PartialEq, Hash)]
 pub enum Celled<T> {

crates/typst-library/src/layout/grid/resolve.rs

@@ -31,14 +31,14 @@ pub fn grid_to_cellgrid<'a>(
     locator: Locator<'a>,
     styles: StyleChain,
 ) -> SourceResult<CellGrid<'a>> {
-    let inset = elem.inset(styles);
-    let align = elem.align(styles);
-    let columns = elem.columns(styles);
-    let rows = elem.rows(styles);
-    let column_gutter = elem.column_gutter(styles);
-    let row_gutter = elem.row_gutter(styles);
-    let fill = elem.fill(styles);
-    let stroke = elem.stroke(styles);
+    let inset = elem.inset.get_cloned(styles);
+    let align = elem.align.get_ref(styles);
+    let columns = elem.columns.get_ref(styles);
+    let rows = elem.rows.get_ref(styles);
+    let column_gutter = elem.column_gutter.get_ref(styles);
+    let row_gutter = elem.row_gutter.get_ref(styles);
+    let fill = elem.fill.get_ref(styles);
+    let stroke = elem.stroke.resolve(styles);
 
     let tracks = Axes::new(columns.0.as_slice(), rows.0.as_slice());
     let gutter = Axes::new(column_gutter.0.as_slice(), row_gutter.0.as_slice());
@@ -47,13 +47,13 @@ pub fn grid_to_cellgrid<'a>(
     let resolve_item = |item: &GridItem| grid_item_to_resolvable(item, styles);
     let children = elem.children.iter().map(|child| match child {
         GridChild::Header(header) => ResolvableGridChild::Header {
-            repeat: header.repeat(styles),
-            level: header.level(styles),
+            repeat: header.repeat.get(styles),
+            level: header.level.get(styles),
             span: header.span(),
             items: header.children.iter().map(resolve_item),
         },
         GridChild::Footer(footer) => ResolvableGridChild::Footer {
-            repeat: footer.repeat(styles),
+            repeat: footer.repeat.get(styles),
             span: footer.span(),
             items: footer.children.iter().map(resolve_item),
         },
@@ -85,14 +85,14 @@ pub fn table_to_cellgrid<'a>(
     locator: Locator<'a>,
     styles: StyleChain,
 ) -> SourceResult<CellGrid<'a>> {
-    let inset = elem.inset(styles);
-    let align = elem.align(styles);
-    let columns = elem.columns(styles);
-    let rows = elem.rows(styles);
-    let column_gutter = elem.column_gutter(styles);
-    let row_gutter = elem.row_gutter(styles);
-    let fill = elem.fill(styles);
-    let stroke = elem.stroke(styles);
+    let inset = elem.inset.get_cloned(styles);
+    let align = elem.align.get_ref(styles);
+    let columns = elem.columns.get_ref(styles);
+    let rows = elem.rows.get_ref(styles);
+    let column_gutter = elem.column_gutter.get_ref(styles);
+    let row_gutter = elem.row_gutter.get_ref(styles);
+    let fill = elem.fill.get_ref(styles);
+    let stroke = elem.stroke.resolve(styles);
 
     let tracks = Axes::new(columns.0.as_slice(), rows.0.as_slice());
     let gutter = Axes::new(column_gutter.0.as_slice(), row_gutter.0.as_slice());
@@ -101,13 +101,13 @@ pub fn table_to_cellgrid<'a>(
     let resolve_item = |item: &TableItem| table_item_to_resolvable(item, styles);
     let children = elem.children.iter().map(|child| match child {
         TableChild::Header(header) => ResolvableGridChild::Header {
-            repeat: header.repeat(styles),
-            level: header.level(styles),
+            repeat: header.repeat.get(styles),
+            level: header.level.get(styles),
             span: header.span(),
             items: header.children.iter().map(resolve_item),
         },
         TableChild::Footer(footer) => ResolvableGridChild::Footer {
-            repeat: footer.repeat(styles),
+            repeat: footer.repeat.get(styles),
             span: footer.span(),
             items: footer.children.iter().map(resolve_item),
         },
@@ -137,27 +137,27 @@ fn grid_item_to_resolvable(
 ) -> ResolvableGridItem<Packed<GridCell>> {
     match item {
         GridItem::HLine(hline) => ResolvableGridItem::HLine {
-            y: hline.y(styles),
-            start: hline.start(styles),
-            end: hline.end(styles),
-            stroke: hline.stroke(styles),
+            y: hline.y.get(styles),
+            start: hline.start.get(styles),
+            end: hline.end.get(styles),
+            stroke: hline.stroke.resolve(styles),
             span: hline.span(),
-            position: match hline.position(styles) {
+            position: match hline.position.get(styles) {
                 OuterVAlignment::Top => LinePosition::Before,
                 OuterVAlignment::Bottom => LinePosition::After,
             },
         },
         GridItem::VLine(vline) => ResolvableGridItem::VLine {
-            x: vline.x(styles),
-            start: vline.start(styles),
-            end: vline.end(styles),
-            stroke: vline.stroke(styles),
+            x: vline.x.get(styles),
+            start: vline.start.get(styles),
+            end: vline.end.get(styles),
+            stroke: vline.stroke.resolve(styles),
             span: vline.span(),
-            position: match vline.position(styles) {
-                OuterHAlignment::Left if TextElem::dir_in(styles) == Dir::RTL => {
+            position: match vline.position.get(styles) {
+                OuterHAlignment::Left if styles.resolve(TextElem::dir) == Dir::RTL => {
                     LinePosition::After
                 }
-                OuterHAlignment::Right if TextElem::dir_in(styles) == Dir::RTL => {
+                OuterHAlignment::Right if styles.resolve(TextElem::dir) == Dir::RTL => {
                     LinePosition::Before
                 }
                 OuterHAlignment::Start | OuterHAlignment::Left => LinePosition::Before,
@@ -174,27 +174,27 @@ fn table_item_to_resolvable(
 ) -> ResolvableGridItem<Packed<TableCell>> {
     match item {
         TableItem::HLine(hline) => ResolvableGridItem::HLine {
-            y: hline.y(styles),
-            start: hline.start(styles),
-            end: hline.end(styles),
-            stroke: hline.stroke(styles),
+            y: hline.y.get(styles),
+            start: hline.start.get(styles),
+            end: hline.end.get(styles),
+            stroke: hline.stroke.resolve(styles),
             span: hline.span(),
-            position: match hline.position(styles) {
+            position: match hline.position.get(styles) {
                 OuterVAlignment::Top => LinePosition::Before,
                 OuterVAlignment::Bottom => LinePosition::After,
             },
         },
         TableItem::VLine(vline) => ResolvableGridItem::VLine {
-            x: vline.x(styles),
-            start: vline.start(styles),
-            end: vline.end(styles),
-            stroke: vline.stroke(styles),
+            x: vline.x.get(styles),
+            start: vline.start.get(styles),
+            end: vline.end.get(styles),
+            stroke: vline.stroke.resolve(styles),
             span: vline.span(),
-            position: match vline.position(styles) {
-                OuterHAlignment::Left if TextElem::dir_in(styles) == Dir::RTL => {
+            position: match vline.position.get(styles) {
+                OuterHAlignment::Left if styles.resolve(TextElem::dir) == Dir::RTL => {
                     LinePosition::After
                 }
-                OuterHAlignment::Right if TextElem::dir_in(styles) == Dir::RTL => {
+                OuterHAlignment::Right if styles.resolve(TextElem::dir) == Dir::RTL => {
                     LinePosition::Before
                 }
                 OuterHAlignment::Start | OuterHAlignment::Left => LinePosition::Before,
@@ -219,12 +219,12 @@ impl ResolvableCell for Packed<TableCell> {
         styles: StyleChain,
     ) -> Cell<'a> {
         let cell = &mut *self;
-        let colspan = cell.colspan(styles);
-        let rowspan = cell.rowspan(styles);
-        let breakable = cell.breakable(styles).unwrap_or(breakable);
-        let fill = cell.fill(styles).unwrap_or_else(|| fill.clone());
+        let colspan = cell.colspan.get(styles);
+        let rowspan = cell.rowspan.get(styles);
+        let breakable = cell.breakable.get(styles).unwrap_or(breakable);
+        let fill = cell.fill.get_cloned(styles).unwrap_or_else(|| fill.clone());
 
-        let cell_stroke = cell.stroke(styles);
+        let cell_stroke = cell.stroke.resolve(styles);
         let stroke_overridden =
             cell_stroke.as_ref().map(|side| matches!(side, Some(Some(_))));
 
@@ -238,22 +238,22 @@ impl ResolvableCell for Packed<TableCell> {
         // cell stroke is the same as specifying 'none', so we equate the two
         // concepts.
         let stroke = cell_stroke.fold(stroke).map(Option::flatten);
-        cell.push_x(Smart::Custom(x));
-        cell.push_y(Smart::Custom(y));
-        cell.push_fill(Smart::Custom(fill.clone()));
-        cell.push_align(match align {
-            Smart::Custom(align) => {
-                Smart::Custom(cell.align(styles).map_or(align, |inner| inner.fold(align)))
-            }
+        cell.x.set(Smart::Custom(x));
+        cell.y.set(Smart::Custom(y));
+        cell.fill.set(Smart::Custom(fill.clone()));
+        cell.align.set(match align {
+            Smart::Custom(align) => Smart::Custom(
+                cell.align.get(styles).map_or(align, |inner| inner.fold(align)),
+            ),
             // Don't fold if the table is using outer alignment. Use the
             // cell's alignment instead (which, in the end, will fold with
             // the outer alignment when it is effectively displayed).
-            Smart::Auto => cell.align(styles),
+            Smart::Auto => cell.align.get(styles),
         });
-        cell.push_inset(Smart::Custom(
-            cell.inset(styles).map_or(inset, |inner| inner.fold(inset)),
+        cell.inset.set(Smart::Custom(
+            cell.inset.get(styles).map_or(inset, |inner| inner.fold(inset)),
         ));
-        cell.push_stroke(
+        cell.stroke.set(
             // Here we convert the resolved stroke to a regular stroke, however
             // with resolved units (that is, 'em' converted to absolute units).
             // We also convert any stroke unspecified by both the cell and the
@@ -266,7 +266,7 @@ impl ResolvableCell for Packed<TableCell> {
                 }))
             }),
         );
-        cell.push_breakable(Smart::Custom(breakable));
+        cell.breakable.set(Smart::Custom(breakable));
         Cell {
             body: self.pack(),
             locator,
@@ -280,19 +280,19 @@ impl ResolvableCell for Packed<TableCell> {
     }
 
     fn x(&self, styles: StyleChain) -> Smart<usize> {
-        (**self).x(styles)
+        self.x.get(styles)
     }
 
     fn y(&self, styles: StyleChain) -> Smart<usize> {
-        (**self).y(styles)
+        self.y.get(styles)
     }
 
     fn colspan(&self, styles: StyleChain) -> NonZeroUsize {
-        (**self).colspan(styles)
+        self.colspan.get(styles)
     }
 
     fn rowspan(&self, styles: StyleChain) -> NonZeroUsize {
-        (**self).rowspan(styles)
+        self.rowspan.get(styles)
     }
 
     fn span(&self) -> Span {
@@ -314,12 +314,12 @@ impl ResolvableCell for Packed<GridCell> {
         styles: StyleChain,
     ) -> Cell<'a> {
         let cell = &mut *self;
-        let colspan = cell.colspan(styles);
-        let rowspan = cell.rowspan(styles);
-        let breakable = cell.breakable(styles).unwrap_or(breakable);
-        let fill = cell.fill(styles).unwrap_or_else(|| fill.clone());
+        let colspan = cell.colspan.get(styles);
+        let rowspan = cell.rowspan.get(styles);
+        let breakable = cell.breakable.get(styles).unwrap_or(breakable);
+        let fill = cell.fill.get_cloned(styles).unwrap_or_else(|| fill.clone());
 
-        let cell_stroke = cell.stroke(styles);
+        let cell_stroke = cell.stroke.resolve(styles);
         let stroke_overridden =
             cell_stroke.as_ref().map(|side| matches!(side, Some(Some(_))));
 
@@ -333,22 +333,22 @@ impl ResolvableCell for Packed<GridCell> {
         // cell stroke is the same as specifying 'none', so we equate the two
         // concepts.
         let stroke = cell_stroke.fold(stroke).map(Option::flatten);
-        cell.push_x(Smart::Custom(x));
-        cell.push_y(Smart::Custom(y));
-        cell.push_fill(Smart::Custom(fill.clone()));
-        cell.push_align(match align {
-            Smart::Custom(align) => {
-                Smart::Custom(cell.align(styles).map_or(align, |inner| inner.fold(align)))
-            }
+        cell.x.set(Smart::Custom(x));
+        cell.y.set(Smart::Custom(y));
+        cell.fill.set(Smart::Custom(fill.clone()));
+        cell.align.set(match align {
+            Smart::Custom(align) => Smart::Custom(
+                cell.align.get(styles).map_or(align, |inner| inner.fold(align)),
+            ),
             // Don't fold if the grid is using outer alignment. Use the
             // cell's alignment instead (which, in the end, will fold with
             // the outer alignment when it is effectively displayed).
-            Smart::Auto => cell.align(styles),
+            Smart::Auto => cell.align.get(styles),
         });
-        cell.push_inset(Smart::Custom(
-            cell.inset(styles).map_or(inset, |inner| inner.fold(inset)),
+        cell.inset.set(Smart::Custom(
+            cell.inset.get(styles).map_or(inset, |inner| inner.fold(inset)),
         ));
-        cell.push_stroke(
+        cell.stroke.set(
             // Here we convert the resolved stroke to a regular stroke, however
             // with resolved units (that is, 'em' converted to absolute units).
             // We also convert any stroke unspecified by both the cell and the
@@ -361,7 +361,7 @@ impl ResolvableCell for Packed<GridCell> {
                 }))
             }),
         );
-        cell.push_breakable(Smart::Custom(breakable));
+        cell.breakable.set(Smart::Custom(breakable));
         Cell {
             body: self.pack(),
             locator,
@@ -375,19 +375,19 @@ impl ResolvableCell for Packed<GridCell> {
     }
 
     fn x(&self, styles: StyleChain) -> Smart<usize> {
-        (**self).x(styles)
+        self.x.get(styles)
     }
 
     fn y(&self, styles: StyleChain) -> Smart<usize> {
-        (**self).y(styles)
+        self.y.get(styles)
     }
 
     fn colspan(&self, styles: StyleChain) -> NonZeroUsize {
-        (**self).colspan(styles)
+        self.colspan.get(styles)
     }
 
     fn rowspan(&self, styles: StyleChain) -> NonZeroUsize {
-        (**self).rowspan(styles)
+        self.rowspan.get(styles)
     }
 
     fn span(&self) -> Span {

crates/typst-library/src/layout/hide.rs

@@ -1,6 +1,4 @@
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{elem, Content, Packed, Show, StyleChain};
+use crate::foundations::{elem, Content};
 
 /// Hides content without affecting layout.
 ///
@@ -14,7 +12,7 @@ use crate::foundations::{elem, Content, Packed, Show, StyleChain};
 /// Hello Jane \
 /// #hide[Hello] Joe
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct HideElem {
     /// The content to hide.
     #[required]
@@ -25,10 +23,3 @@ pub struct HideElem {
     #[ghost]
     pub hidden: bool,
 }
-
-impl Show for Packed<HideElem> {
-    #[typst_macros::time(name = "hide", span = self.span())]
-    fn show(&self, _: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(self.body.clone().styled(HideElem::set_hidden(true)))
-    }
-}

crates/typst-library/src/layout/layout.rs

@@ -1,13 +1,7 @@
-use comemo::Track;
 use typst_syntax::Span;
 
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{
-    dict, elem, func, Content, Context, Func, NativeElement, Packed, Show, StyleChain,
-};
+use crate::foundations::{elem, func, Content, Func, NativeElement};
 use crate::introspection::Locatable;
-use crate::layout::{BlockElem, Size};
 
 /// Provides access to the current outer container's (or page's, if none)
 /// dimensions (width and height).
@@ -86,37 +80,9 @@ pub fn layout(
 }
 
 /// Executes a `layout` call.
-#[elem(Locatable, Show)]
-struct LayoutElem {
+#[elem(Locatable)]
+pub struct LayoutElem {
     /// The function to call with the outer container's (or page's) size.
     #[required]
-    func: Func,
-}
-
-impl Show for Packed<LayoutElem> {
-    fn show(&self, _: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::multi_layouter(
-            self.clone(),
-            |elem, engine, locator, styles, regions| {
-                // Gets the current region's base size, which will be the size of the
-                // outer container, or of the page if there is no such container.
-                let Size { x, y } = regions.base();
-                let loc = elem.location().unwrap();
-                let context = Context::new(Some(loc), Some(styles));
-                let result = elem
-                    .func
-                    .call(
-                        engine,
-                        context.track(),
-                        [dict! { "width" => x, "height" => y }],
-                    )?
-                    .display();
-                (engine.routines.layout_fragment)(
-                    engine, &result, locator, styles, regions,
-                )
-            },
-        )
-        .pack()
-        .spanned(self.span()))
-    }
+    pub func: Func,
 }

crates/typst-library/src/layout/pad.rs

@@ -1,7 +1,5 @@
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{elem, Content, NativeElement, Packed, Show, StyleChain};
-use crate::layout::{BlockElem, Length, Rel};
+use crate::foundations::{elem, Content};
+use crate::layout::{Length, Rel};
 
 /// Adds spacing around content.
 ///
@@ -16,7 +14,7 @@ use crate::layout::{BlockElem, Length, Rel};
 /// _Typing speeds can be
 ///  measured in words per minute._
 /// ```
-#[elem(title = "Padding", Show)]
+#[elem(title = "Padding")]
 pub struct PadElem {
     /// The padding at the left side.
     #[parse(
@@ -55,11 +53,3 @@ pub struct PadElem {
     #[required]
     pub body: Content,
 }
-
-impl Show for Packed<PadElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::multi_layouter(self.clone(), engine.routines.layout_pad)
-            .pack()
-            .spanned(self.span()))
-    }
-}

crates/typst-library/src/layout/page.rs

@@ -60,7 +60,6 @@ pub struct PageElem {
     ///   box(square(width: 1cm))
     /// }
     /// ```
-    #[resolve]
     #[parse(
         let paper = args.named_or_find::<Paper>("paper")?;
         args.named("width")?
@@ -77,7 +76,6 @@ pub struct PageElem {
     /// page set rule. Most examples throughout this documentation use `{auto}`
     /// for the height of the page to dynamically grow and shrink to fit their
     /// content.
-    #[resolve]
     #[parse(
         args.named("height")?
             .or_else(|| paper.map(|paper| Smart::Custom(paper.height().into())))
@@ -201,7 +199,6 @@ pub struct PageElem {
     /// #set text(fill: rgb("fdfdfd"))
     /// *Dark mode enabled.*
     /// ```
-    #[borrowed]
     #[ghost]
     pub fill: Smart<Option<Paint>>,
 
@@ -219,7 +216,6 @@ pub struct PageElem {
     ///
     /// #lorem(48)
     /// ```
-    #[borrowed]
     #[ghost]
     pub numbering: Option<Numbering>,
 
@@ -276,12 +272,10 @@ pub struct PageElem {
     ///
     /// #lorem(19)
     /// ```
-    #[borrowed]
     #[ghost]
     pub header: Smart<Option<Content>>,
 
     /// The amount the header is raised into the top margin.
-    #[resolve]
     #[default(Ratio::new(0.3).into())]
     #[ghost]
     pub header_ascent: Rel<Length>,
@@ -314,12 +308,10 @@ pub struct PageElem {
     ///
     /// #lorem(48)
     /// ```
-    #[borrowed]
     #[ghost]
     pub footer: Smart<Option<Content>>,
 
     /// The amount the footer is lowered into the bottom margin.
-    #[resolve]
     #[default(Ratio::new(0.3).into())]
     #[ghost]
     pub footer_descent: Rel<Length>,
@@ -340,7 +332,6 @@ pub struct PageElem {
     /// In the year 2023, we plan to take
     /// over the world (of typesetting).
     /// ```
-    #[borrowed]
     #[ghost]
     pub background: Option<Content>,
 
@@ -355,7 +346,6 @@ pub struct PageElem {
     /// "Weak Reject" because they did
     /// not understand our approach...
     /// ```
-    #[borrowed]
     #[ghost]
     pub foreground: Option<Content>,
 

crates/typst-library/src/layout/place.rs

@@ -134,7 +134,6 @@ pub struct PlaceElem {
     ///
     /// Has no effect if `float` is `{false}`.
     #[default(Em::new(1.5).into())]
-    #[resolve]
     pub clearance: Length,
 
     /// The horizontal displacement of the placed content.

crates/typst-library/src/layout/repeat.rs

@@ -1,7 +1,5 @@
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{elem, Content, NativeElement, Packed, Show, StyleChain};
-use crate::layout::{BlockElem, Length};
+use crate::foundations::{elem, Content};
+use crate::layout::Length;
 
 /// Repeats content to the available space.
 ///
@@ -24,7 +22,7 @@ use crate::layout::{BlockElem, Length};
 ///   Berlin, the 22nd of December, 2022
 /// ]
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct RepeatElem {
     /// The content to repeat.
     #[required]
@@ -39,11 +37,3 @@ pub struct RepeatElem {
     #[default(true)]
     pub justify: bool,
 }
-
-impl Show for Packed<RepeatElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::single_layouter(self.clone(), engine.routines.layout_repeat)
-            .pack()
-            .spanned(self.span()))
-    }
-}

crates/typst-library/src/layout/stack.rs

@@ -1,9 +1,7 @@
 use std::fmt::{self, Debug, Formatter};
 
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{cast, elem, Content, NativeElement, Packed, Show, StyleChain};
-use crate::layout::{BlockElem, Dir, Spacing};
+use crate::foundations::{cast, elem, Content};
+use crate::layout::{Dir, Spacing};
 
 /// Arranges content and spacing horizontally or vertically.
 ///
@@ -19,7 +17,7 @@ use crate::layout::{BlockElem, Dir, Spacing};
 ///   rect(width: 90pt),
 /// )
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct StackElem {
     /// The direction along which the items are stacked. Possible values are:
     ///
@@ -47,14 +45,6 @@ pub struct StackElem {
     pub children: Vec<StackChild>,
 }
 
-impl Show for Packed<StackElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::multi_layouter(self.clone(), engine.routines.layout_stack)
-            .pack()
-            .spanned(self.span()))
-    }
-}
-
 /// A child of a stack element.
 #[derive(Clone, PartialEq, Hash)]
 pub enum StackChild {

crates/typst-library/src/layout/transform.rs

@@ -1,11 +1,5 @@
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{
-    cast, elem, Content, NativeElement, Packed, Show, Smart, StyleChain,
-};
-use crate::layout::{
-    Abs, Alignment, Angle, BlockElem, HAlignment, Length, Ratio, Rel, VAlignment,
-};
+use crate::foundations::{cast, elem, Content, Smart};
+use crate::layout::{Abs, Alignment, Angle, HAlignment, Length, Ratio, Rel, VAlignment};
 
 /// Moves content without affecting layout.
 ///
@@ -25,7 +19,7 @@ use crate::layout::{
 ///   )
 /// ))
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct MoveElem {
     /// The horizontal displacement of the content.
     pub dx: Rel<Length>,
@@ -38,14 +32,6 @@ pub struct MoveElem {
     pub body: Content,
 }
 
-impl Show for Packed<MoveElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::single_layouter(self.clone(), engine.routines.layout_move)
-            .pack()
-            .spanned(self.span()))
-    }
-}
-
 /// Rotates content without affecting layout.
 ///
 /// Rotates an element by a given angle. The layout will act as if the element
@@ -60,7 +46,7 @@ impl Show for Packed<MoveElem> {
 ///     .map(i => rotate(24deg * i)[X]),
 /// )
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct RotateElem {
     /// The amount of rotation.
     ///
@@ -107,14 +93,6 @@ pub struct RotateElem {
     pub body: Content,
 }
 
-impl Show for Packed<RotateElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::single_layouter(self.clone(), engine.routines.layout_rotate)
-            .pack()
-            .spanned(self.span()))
-    }
-}
-
 /// Scales content without affecting layout.
 ///
 /// Lets you mirror content by specifying a negative scale on a single axis.
@@ -125,7 +103,7 @@ impl Show for Packed<RotateElem> {
 /// #scale(x: -100%)[This is mirrored.]
 /// #scale(x: -100%, reflow: true)[This is mirrored.]
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct ScaleElem {
     /// The scaling factor for both axes, as a positional argument. This is just
     /// an optional shorthand notation for setting `x` and `y` to the same
@@ -179,14 +157,6 @@ pub struct ScaleElem {
     pub body: Content,
 }
 
-impl Show for Packed<ScaleElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::single_layouter(self.clone(), engine.routines.layout_scale)
-            .pack()
-            .spanned(self.span()))
-    }
-}
-
 /// To what size something shall be scaled.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub enum ScaleAmount {
@@ -215,7 +185,7 @@ cast! {
 ///   This is some fake italic text.
 /// ]
 /// ```
-#[elem(Show)]
+#[elem]
 pub struct SkewElem {
     /// The horizontal skewing angle.
     ///
@@ -265,14 +235,6 @@ pub struct SkewElem {
     pub body: Content,
 }
 
-impl Show for Packed<SkewElem> {
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
-        Ok(BlockElem::single_layouter(self.clone(), engine.routines.layout_skew)
-            .pack()
-            .spanned(self.span()))
-    }
-}
-
 /// A scale-skew-translate transformation.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub struct Transform {

crates/typst-library/src/lib.rs

@@ -36,6 +36,7 @@ use typst_utils::{LazyHash, SmallBitSet};
 use crate::diag::FileResult;
 use crate::foundations::{Array, Binding, Bytes, Datetime, Dict, Module, Scope, Styles};
 use crate::layout::{Alignment, Dir};
+use crate::routines::Routines;
 use crate::text::{Font, FontBook};
 use crate::visualize::Color;
 
@@ -139,6 +140,11 @@ impl<T: World + ?Sized> WorldExt for T {
 }
 
 /// Definition of Typst's standard library.
+///
+/// To create and configure the standard library, use the `LibraryExt` trait
+/// and call
+/// - `Library::default()` for a standard configuration
+/// - `Library::builder().build()` if you want to customize the library
 #[derive(Debug, Clone, Hash)]
 pub struct Library {
     /// The module that contains the definitions that are available everywhere.
@@ -154,30 +160,27 @@ pub struct Library {
     pub features: Features,
 }
 
-impl Library {
-    /// Create a new builder for a library.
-    pub fn builder() -> LibraryBuilder {
-        LibraryBuilder::default()
-    }
-}
-
-impl Default for Library {
-    /// Constructs the standard library with the default configuration.
-    fn default() -> Self {
-        Self::builder().build()
-    }
-}
-
 /// Configurable builder for the standard library.
 ///
-/// This struct is created by [`Library::builder`].
-#[derive(Debug, Clone, Default)]
+/// Constructed via the `LibraryExt` trait.
+#[derive(Debug, Clone)]
 pub struct LibraryBuilder {
+    routines: &'static Routines,
     inputs: Option<Dict>,
     features: Features,
 }
 
 impl LibraryBuilder {
+    /// Creates a new builder.
+    #[doc(hidden)]
+    pub fn from_routines(routines: &'static Routines) -> Self {
+        Self {
+            routines,
+            inputs: None,
+            features: Features::default(),
+        }
+    }
+
     /// Configure the inputs visible through `sys.inputs`.
     pub fn with_inputs(mut self, inputs: Dict) -> Self {
         self.inputs = Some(inputs);
@@ -196,7 +199,7 @@ impl LibraryBuilder {
     pub fn build(self) -> Library {
         let math = math::module();
         let inputs = self.inputs.unwrap_or_default();
-        let global = global(math.clone(), inputs, &self.features);
+        let global = global(self.routines, math.clone(), inputs, &self.features);
         Library {
             global: global.clone(),
             math,
@@ -278,7 +281,12 @@ impl Category {
 }
 
 /// Construct the module with global definitions.
-fn global(math: Module, inputs: Dict, features: &Features) -> Module {
+fn global(
+    routines: &Routines,
+    math: Module,
+    inputs: Dict,
+    features: &Features,
+) -> Module {
     let mut global = Scope::deduplicating();
 
     self::foundations::define(&mut global, inputs, features);
@@ -293,7 +301,7 @@ fn global(math: Module, inputs: Dict, features: &Features) -> Module {
     global.define("math", math);
     global.define("pdf", self::pdf::module());
     if features.is_enabled(Feature::Html) {
-        global.define("html", self::html::module());
+        global.define("html", (routines.html_module)());
     }
 
     prelude(&mut global);

crates/typst-library/src/math/accent.rs

@@ -62,7 +62,6 @@ pub struct AccentElem {
     /// ```example
     /// $dash(A, size: #150%)$
     /// ```
-    #[resolve]
     #[default(Rel::one())]
     pub size: Rel<Length>,
 

crates/typst-library/src/math/attach.rs

@@ -59,9 +59,9 @@ impl Packed<AttachElem> {
 
             macro_rules! merge {
                 ($content:ident) => {
-                    if base.$content.is_none() && elem.$content.is_some() {
+                    if !base.$content.is_set() && elem.$content.is_set() {
                         base.$content = elem.$content.clone();
-                        elem.$content = None;
+                        elem.$content.unset();
                     }
                 };
             }
@@ -152,7 +152,6 @@ pub struct StretchElem {
 
     /// The size to stretch to, relative to the maximum size of the glyph and
     /// its attachments.
-    #[resolve]
     #[default(Rel::one())]
     pub size: Rel<Length>,
 }

crates/typst-library/src/math/cancel.rs

@@ -29,7 +29,6 @@ pub struct CancelElem {
     /// $ a + cancel(x, length: #200%)
     ///     - cancel(x, length: #200%) $
     /// ```
-    #[resolve]
     #[default(Rel::new(Ratio::one(), Abs::pt(3.0).into()))]
     pub length: Rel<Length>,
 
@@ -89,7 +88,6 @@ pub struct CancelElem {
     ///   ),
     /// ) $
     /// ```
-    #[resolve]
     #[fold]
     #[default(Stroke {
         // Default stroke has 0.5pt for better visuals.

crates/typst-library/src/math/equation.rs

@@ -6,13 +6,11 @@ use unicode_math_class::MathClass;
 use crate::diag::SourceResult;
 use crate::engine::Engine;
 use crate::foundations::{
-    elem, Content, NativeElement, Packed, Show, ShowSet, Smart, StyleChain, Styles,
-    Synthesize,
+    elem, Content, NativeElement, Packed, ShowSet, Smart, StyleChain, Styles, Synthesize,
 };
 use crate::introspection::{Count, Counter, CounterUpdate, Locatable};
 use crate::layout::{
-    AlignElem, Alignment, BlockElem, InlineElem, OuterHAlignment, SpecificAlignment,
-    VAlignment,
+    AlignElem, Alignment, BlockElem, OuterHAlignment, SpecificAlignment, VAlignment,
 };
 use crate::math::{MathSize, MathVariant};
 use crate::model::{Numbering, Outlinable, ParLine, Refable, Supplement};
@@ -46,7 +44,7 @@ use crate::text::{FontFamily, FontList, FontWeight, LocalName, TextElem};
 /// least one space lifts it into a separate block that is centered
 /// horizontally. For more details about math syntax, see the
 /// [main math page]($category/math).
-#[elem(Locatable, Synthesize, Show, ShowSet, Count, LocalName, Refable, Outlinable)]
+#[elem(Locatable, Synthesize, ShowSet, Count, LocalName, Refable, Outlinable)]
 pub struct EquationElem {
     /// Whether the equation is displayed as a separate block.
     #[default(false)]
@@ -63,7 +61,6 @@ pub struct EquationElem {
     /// With @ratio, we get:
     /// $ F_n = floor(1 / sqrt(5) phi.alt^n) $
     /// ```
-    #[borrowed]
     pub numbering: Option<Numbering>,
 
     /// The alignment of the equation numbering.
@@ -152,7 +149,7 @@ impl Synthesize for Packed<EquationElem> {
         engine: &mut Engine,
         styles: StyleChain,
     ) -> SourceResult<()> {
-        let supplement = match self.as_ref().supplement(styles) {
+        let supplement = match self.as_ref().supplement.get_ref(styles) {
             Smart::Auto => TextElem::packed(Self::local_name_in(styles)),
             Smart::Custom(None) => Content::empty(),
             Smart::Custom(Some(supplement)) => {
@@ -160,50 +157,36 @@ impl Synthesize for Packed<EquationElem> {
             }
         };
 
-        self.push_supplement(Smart::Custom(Some(Supplement::Content(supplement))));
+        self.supplement
+            .set(Smart::Custom(Some(Supplement::Content(supplement))));
         Ok(())
     }
 }
 
-impl Show for Packed<EquationElem> {
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        if self.block(styles) {
-            Ok(BlockElem::multi_layouter(
-                self.clone(),
-                engine.routines.layout_equation_block,
-            )
-            .pack()
-            .spanned(self.span()))
-        } else {
-            Ok(InlineElem::layouter(self.clone(), engine.routines.layout_equation_inline)
-                .pack()
-                .spanned(self.span()))
-        }
-    }
-}
-
 impl ShowSet for Packed<EquationElem> {
     fn show_set(&self, styles: StyleChain) -> Styles {
         let mut out = Styles::new();
-        if self.block(styles) {
-            out.set(AlignElem::set_alignment(Alignment::CENTER));
-            out.set(BlockElem::set_breakable(false));
-            out.set(ParLine::set_numbering(None));
-            out.set(EquationElem::set_size(MathSize::Display));
+        if self.block.get(styles) {
+            out.set(AlignElem::alignment, Alignment::CENTER);
+            out.set(AlignElem::alignment, Alignment::CENTER);
+            out.set(BlockElem::breakable, false);
+            out.set(ParLine::numbering, None);
+            out.set(EquationElem::size, MathSize::Display);
         } else {
-            out.set(EquationElem::set_size(MathSize::Text));
+            out.set(EquationElem::size, MathSize::Text);
         }
-        out.set(TextElem::set_weight(FontWeight::from_number(450)));
-        out.set(TextElem::set_font(FontList(vec![FontFamily::new(
-            "New Computer Modern Math",
-        )])));
+        out.set(TextElem::weight, FontWeight::from_number(450));
+        out.set(
+            TextElem::font,
+            FontList(vec![FontFamily::new("New Computer Modern Math")]),
+        );
         out
     }
 }
 
 impl Count for Packed<EquationElem> {
     fn update(&self) -> Option<CounterUpdate> {
-        (self.block(StyleChain::default()) && self.numbering().is_some())
+        (self.block.get(StyleChain::default()) && self.numbering().is_some())
             .then(|| CounterUpdate::Step(NonZeroUsize::ONE))
     }
 }
@@ -215,24 +198,24 @@ impl LocalName for Packed<EquationElem> {
 impl Refable for Packed<EquationElem> {
     fn supplement(&self) -> Content {
         // After synthesis, this should always be custom content.
-        match (**self).supplement(StyleChain::default()) {
+        match self.supplement.get_cloned(StyleChain::default()) {
             Smart::Custom(Some(Supplement::Content(content))) => content,
             _ => Content::empty(),
         }
     }
 
     fn counter(&self) -> Counter {
-        Counter::of(EquationElem::elem())
+        Counter::of(EquationElem::ELEM)
     }
 
     fn numbering(&self) -> Option<&Numbering> {
-        (**self).numbering(StyleChain::default()).as_ref()
+        self.numbering.get_ref(StyleChain::default()).as_ref()
     }
 }
 
 impl Outlinable for Packed<EquationElem> {
     fn outlined(&self) -> bool {
-        self.block(StyleChain::default()) && self.numbering().is_some()
+        self.block.get(StyleChain::default()) && self.numbering().is_some()
     }
 
     fn prefix(&self, numbers: Content) -> Content {

crates/typst-library/src/math/lr.rs

@@ -9,7 +9,6 @@ use crate::math::Mathy;
 #[elem(title = "Left/Right", Mathy)]
 pub struct LrElem {
     /// The size of the brackets, relative to the height of the wrapped content.
-    #[resolve]
     #[default(Rel::one())]
     pub size: Rel<Length>,
 
@@ -130,7 +129,7 @@ fn delimited(
     ]));
     // Push size only if size is provided
     if let Some(size) = size {
-        elem.push_size(size);
+        elem.size.set(size);
     }
     elem.pack().spanned(span)
 }

crates/typst-library/src/math/matrix.rs

@@ -46,7 +46,6 @@ pub struct VecElem {
     /// #set math.vec(align: right)
     /// $ vec(-1, 1, -1) $
     /// ```
-    #[resolve]
     #[default(HAlignment::Center)]
     pub align: HAlignment,
 
@@ -56,7 +55,6 @@ pub struct VecElem {
     /// #set math.vec(gap: 1em)
     /// $ vec(1, 2) $
     /// ```
-    #[resolve]
     #[default(DEFAULT_ROW_GAP.into())]
     pub gap: Rel<Length>,
 
@@ -107,7 +105,6 @@ pub struct MatElem {
     /// #set math.mat(align: right)
     /// $ mat(-1, 1, 1; 1, -1, 1; 1, 1, -1) $
     /// ```
-    #[resolve]
     #[default(HAlignment::Center)]
     pub align: HAlignment,
 
@@ -141,7 +138,6 @@ pub struct MatElem {
     /// ```example
     /// $ mat(0, 0, 0; 1, 1, 1; augment: #(hline: 1, stroke: 2pt + green)) $
     /// ```
-    #[resolve]
     #[fold]
     pub augment: Option<Augment>,
 
@@ -162,7 +158,6 @@ pub struct MatElem {
     /// #set math.mat(row-gap: 1em)
     /// $ mat(1, 2; 3, 4) $
     /// ```
-    #[resolve]
     #[parse(
         let gap = args.named("gap")?;
         args.named("row-gap")?.or(gap)
@@ -176,7 +171,6 @@ pub struct MatElem {
     /// #set math.mat(column-gap: 1em)
     /// $ mat(1, 2; 3, 4) $
     /// ```
-    #[resolve]
     #[parse(args.named("column-gap")?.or(gap))]
     #[default(DEFAULT_COL_GAP.into())]
     pub column_gap: Rel<Length>,
@@ -259,7 +253,6 @@ pub struct CasesElem {
     /// #set math.cases(gap: 1em)
     /// $ x = cases(1, 2) $
     /// ```
-    #[resolve]
     #[default(DEFAULT_ROW_GAP.into())]
     pub gap: Rel<Length>,
 

crates/typst-library/src/math/style.rs

@@ -11,7 +11,7 @@ pub fn bold(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_bold(true))
+    body.set(EquationElem::bold, true)
 }
 
 /// Upright (non-italic) font style in math.
@@ -24,7 +24,7 @@ pub fn upright(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_italic(Smart::Custom(false)))
+    body.set(EquationElem::italic, Smart::Custom(false))
 }
 
 /// Italic font style in math.
@@ -35,7 +35,7 @@ pub fn italic(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_italic(Smart::Custom(true)))
+    body.set(EquationElem::italic, Smart::Custom(true))
 }
 
 /// Serif (roman) font style in math.
@@ -46,7 +46,7 @@ pub fn serif(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_variant(MathVariant::Serif))
+    body.set(EquationElem::variant, MathVariant::Serif)
 }
 
 /// Sans-serif font style in math.
@@ -59,7 +59,7 @@ pub fn sans(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_variant(MathVariant::Sans))
+    body.set(EquationElem::variant, MathVariant::Sans)
 }
 
 /// Calligraphic font style in math.
@@ -93,7 +93,7 @@ pub fn cal(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_variant(MathVariant::Cal))
+    body.set(EquationElem::variant, MathVariant::Cal)
 }
 
 /// Fraktur font style in math.
@@ -106,7 +106,7 @@ pub fn frak(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_variant(MathVariant::Frak))
+    body.set(EquationElem::variant, MathVariant::Frak)
 }
 
 /// Monospace font style in math.
@@ -119,7 +119,7 @@ pub fn mono(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_variant(MathVariant::Mono))
+    body.set(EquationElem::variant, MathVariant::Mono)
 }
 
 /// Blackboard bold (double-struck) font style in math.
@@ -137,7 +137,7 @@ pub fn bb(
     /// The content to style.
     body: Content,
 ) -> Content {
-    body.styled(EquationElem::set_variant(MathVariant::Bb))
+    body.set(EquationElem::variant, MathVariant::Bb)
 }
 
 /// Forced display style in math.
@@ -157,8 +157,8 @@ pub fn display(
     #[default(false)]
     cramped: bool,
 ) -> Content {
-    body.styled(EquationElem::set_size(MathSize::Display))
-        .styled(EquationElem::set_cramped(cramped))
+    body.set(EquationElem::size, MathSize::Display)
+        .set(EquationElem::cramped, cramped)
 }
 
 /// Forced inline (text) style in math.
@@ -179,8 +179,8 @@ pub fn inline(
     #[default(false)]
     cramped: bool,
 ) -> Content {
-    body.styled(EquationElem::set_size(MathSize::Text))
-        .styled(EquationElem::set_cramped(cramped))
+    body.set(EquationElem::size, MathSize::Text)
+        .set(EquationElem::cramped, cramped)
 }
 
 /// Forced script style in math.
@@ -200,8 +200,8 @@ pub fn script(
     #[default(true)]
     cramped: bool,
 ) -> Content {
-    body.styled(EquationElem::set_size(MathSize::Script))
-        .styled(EquationElem::set_cramped(cramped))
+    body.set(EquationElem::size, MathSize::Script)
+        .set(EquationElem::cramped, cramped)
 }
 
 /// Forced second script style in math.
@@ -222,8 +222,8 @@ pub fn sscript(
     #[default(true)]
     cramped: bool,
 ) -> Content {
-    body.styled(EquationElem::set_size(MathSize::ScriptScript))
-        .styled(EquationElem::set_cramped(cramped))
+    body.set(EquationElem::size, MathSize::ScriptScript)
+        .set(EquationElem::cramped, cramped)
 }
 
 /// The size of elements in an equation.

crates/typst-library/src/model/bibliography.rs

@@ -2,7 +2,6 @@ use std::any::TypeId;
 use std::collections::HashMap;
 use std::ffi::OsStr;
 use std::fmt::{self, Debug, Formatter};
-use std::num::NonZeroUsize;
 use std::path::Path;
 use std::sync::{Arc, LazyLock};
 
@@ -17,7 +16,7 @@ use hayagriva::{
 use indexmap::IndexMap;
 use smallvec::{smallvec, SmallVec};
 use typst_syntax::{Span, Spanned, SyntaxMode};
-use typst_utils::{Get, ManuallyHash, NonZeroExt, PicoStr};
+use typst_utils::{ManuallyHash, PicoStr};
 
 use crate::diag::{
     bail, error, At, HintedStrResult, LoadError, LoadResult, LoadedWithin, ReportPos,
@@ -26,18 +25,17 @@ use crate::diag::{
 use crate::engine::{Engine, Sink};
 use crate::foundations::{
     elem, Bytes, CastInfo, Content, Derived, FromValue, IntoValue, Label, NativeElement,
-    OneOrMultiple, Packed, Reflect, Scope, Show, ShowSet, Smart, StyleChain, Styles,
+    OneOrMultiple, Packed, Reflect, Scope, ShowSet, Smart, StyleChain, Styles,
     Synthesize, Value,
 };
 use crate::introspection::{Introspector, Locatable, Location};
 use crate::layout::{
     BlockBody, BlockElem, Em, GridCell, GridChild, GridElem, GridItem, HElem, PadElem,
-    Sides, Sizing, TrackSizings,
+    Sizing, TrackSizings,
 };
 use crate::loading::{format_yaml_error, DataSource, Load, LoadSource, Loaded};
 use crate::model::{
-    CitationForm, CiteGroup, Destination, FootnoteElem, HeadingElem, LinkElem, ParElem,
-    Url,
+    CitationForm, CiteGroup, Destination, FootnoteElem, HeadingElem, LinkElem, Url,
 };
 use crate::routines::Routines;
 use crate::text::{
@@ -88,7 +86,7 @@ use crate::World;
 ///
 /// #bibliography("works.bib")
 /// ```
-#[elem(Locatable, Synthesize, Show, ShowSet, LocalName)]
+#[elem(Locatable, Synthesize, ShowSet, LocalName)]
 pub struct BibliographyElem {
     /// One or multiple paths to or raw bytes for Hayagriva `.yaml` and/or
     /// BibLaTeX `.bib` files.
@@ -158,7 +156,7 @@ pub struct BibliographyElem {
 impl BibliographyElem {
     /// Find the document's bibliography.
     pub fn find(introspector: Tracked<Introspector>) -> StrResult<Packed<Self>> {
-        let query = introspector.query(&Self::elem().select());
+        let query = introspector.query(&Self::ELEM.select());
         let mut iter = query.iter();
         let Some(elem) = iter.next() else {
             bail!("the document does not contain a bibliography");
@@ -175,7 +173,7 @@ impl BibliographyElem {
     pub fn has(engine: &Engine, key: Label) -> bool {
         engine
             .introspector
-            .query(&Self::elem().select())
+            .query(&Self::ELEM.select())
             .iter()
             .any(|elem| elem.to_packed::<Self>().unwrap().sources.derived.has(key))
     }
@@ -183,7 +181,7 @@ impl BibliographyElem {
     /// Find all bibliography keys.
     pub fn keys(introspector: Tracked<Introspector>) -> Vec<(Label, Option<EcoString>)> {
         let mut vec = vec![];
-        for elem in introspector.query(&Self::elem().select()).iter() {
+        for elem in introspector.query(&Self::ELEM.select()).iter() {
             let this = elem.to_packed::<Self>().unwrap();
             for (key, entry) in this.sources.derived.iter() {
                 let detail = entry.title().map(|title| title.value.to_str().into());
@@ -197,96 +195,18 @@ impl BibliographyElem {
 impl Synthesize for Packed<BibliographyElem> {
     fn synthesize(&mut self, _: &mut Engine, styles: StyleChain) -> SourceResult<()> {
         let elem = self.as_mut();
-        elem.push_lang(TextElem::lang_in(styles));
-        elem.push_region(TextElem::region_in(styles));
+        elem.lang = Some(styles.get(TextElem::lang));
+        elem.region = Some(styles.get(TextElem::region));
         Ok(())
     }
 }
 
-impl Show for Packed<BibliographyElem> {
-    #[typst_macros::time(name = "bibliography", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        const COLUMN_GUTTER: Em = Em::new(0.65);
-        const INDENT: Em = Em::new(1.5);
-
-        let span = self.span();
-
-        let mut seq = vec![];
-        if let Some(title) = self.title(styles).unwrap_or_else(|| {
-            Some(TextElem::packed(Self::local_name_in(styles)).spanned(span))
-        }) {
-            seq.push(
-                HeadingElem::new(title)
-                    .with_depth(NonZeroUsize::ONE)
-                    .pack()
-                    .spanned(span),
-            );
-        }
-
-        let works = Works::generate(engine).at(span)?;
-        let references = works
-            .references
-            .as_ref()
-            .ok_or_else(|| match self.style(styles).source {
-                CslSource::Named(style) => eco_format!(
-                    "CSL style \"{}\" is not suitable for bibliographies",
-                    style.display_name()
-                ),
-                CslSource::Normal(..) => {
-                    "CSL style is not suitable for bibliographies".into()
-                }
-            })
-            .at(span)?;
-
-        if references.iter().any(|(prefix, _)| prefix.is_some()) {
-            let row_gutter = ParElem::spacing_in(styles);
-
-            let mut cells = vec![];
-            for (prefix, reference) in references {
-                cells.push(GridChild::Item(GridItem::Cell(
-                    Packed::new(GridCell::new(prefix.clone().unwrap_or_default()))
-                        .spanned(span),
-                )));
-                cells.push(GridChild::Item(GridItem::Cell(
-                    Packed::new(GridCell::new(reference.clone())).spanned(span),
-                )));
-            }
-            seq.push(
-                GridElem::new(cells)
-                    .with_columns(TrackSizings(smallvec![Sizing::Auto; 2]))
-                    .with_column_gutter(TrackSizings(smallvec![COLUMN_GUTTER.into()]))
-                    .with_row_gutter(TrackSizings(smallvec![row_gutter.into()]))
-                    .pack()
-                    .spanned(span),
-            );
-        } else {
-            for (_, reference) in references {
-                let realized = reference.clone();
-                let block = if works.hanging_indent {
-                    let body = HElem::new((-INDENT).into()).pack() + realized;
-                    let inset = Sides::default()
-                        .with(TextElem::dir_in(styles).start(), Some(INDENT.into()));
-                    BlockElem::new()
-                        .with_body(Some(BlockBody::Content(body)))
-                        .with_inset(inset)
-                } else {
-                    BlockElem::new().with_body(Some(BlockBody::Content(realized)))
-                };
-
-                seq.push(block.pack().spanned(span));
-            }
-        }
-
-        Ok(Content::sequence(seq))
-    }
-}
-
 impl ShowSet for Packed<BibliographyElem> {
     fn show_set(&self, _: StyleChain) -> Styles {
         const INDENT: Em = Em::new(1.0);
         let mut out = Styles::new();
-        out.set(HeadingElem::set_numbering(None));
-        out.set(PadElem::set_left(INDENT.into()));
+        out.set(HeadingElem::numbering, None);
+        out.set(PadElem::left, INDENT.into());
         out
     }
 }
@@ -564,7 +484,7 @@ impl IntoValue for CslSource {
 /// memoization) for the whole document. This setup is necessary because
 /// citation formatting is inherently stateful and we need access to all
 /// citations to do it.
-pub(super) struct Works {
+pub struct Works {
     /// Maps from the location of a citation group to its rendered content.
     pub citations: HashMap<Location, SourceResult<Content>>,
     /// Lists all references in the bibliography, with optional prefix, or
@@ -643,7 +563,7 @@ impl<'a> Generator<'a> {
         introspector: Tracked<Introspector>,
     ) -> StrResult<Self> {
         let bibliography = BibliographyElem::find(introspector)?;
-        let groups = introspector.query(&CiteGroup::elem().select());
+        let groups = introspector.query(&CiteGroup::ELEM.select());
         let infos = Vec::with_capacity(groups.len());
         Ok(Self {
             routines,
@@ -661,7 +581,8 @@ impl<'a> Generator<'a> {
             LazyLock::new(hayagriva::archive::locales);
 
         let database = &self.bibliography.sources.derived;
-        let bibliography_style = &self.bibliography.style(StyleChain::default()).derived;
+        let bibliography_style =
+            &self.bibliography.style.get_ref(StyleChain::default()).derived;
 
         // Process all citation groups.
         let mut driver = BibliographyDriver::new();
@@ -689,7 +610,7 @@ impl<'a> Generator<'a> {
                     continue;
                 };
 
-                let supplement = child.supplement(StyleChain::default());
+                let supplement = child.supplement.get_cloned(StyleChain::default());
                 let locator = supplement.as_ref().map(|_| {
                     SpecificLocator(
                         citationberg::taxonomy::Locator::Custom,
@@ -698,7 +619,7 @@ impl<'a> Generator<'a> {
                 });
 
                 let mut hidden = false;
-                let special_form = match child.form(StyleChain::default()) {
+                let special_form = match child.form.get(StyleChain::default()) {
                     None => {
                         hidden = true;
                         None
@@ -720,7 +641,7 @@ impl<'a> Generator<'a> {
                 continue;
             }
 
-            let style = match first.style(StyleChain::default()) {
+            let style = match first.style.get_ref(StyleChain::default()) {
                 Smart::Auto => bibliography_style.get(),
                 Smart::Custom(style) => style.derived.get(),
             };
@@ -736,23 +657,20 @@ impl<'a> Generator<'a> {
             driver.citation(CitationRequest::new(
                 items,
                 style,
-                Some(locale(
-                    first.lang().copied().unwrap_or(Lang::ENGLISH),
-                    first.region().copied().flatten(),
-                )),
+                Some(locale(first.lang.unwrap_or(Lang::ENGLISH), first.region.flatten())),
                 &LOCALES,
                 None,
             ));
         }
 
         let locale = locale(
-            self.bibliography.lang().copied().unwrap_or(Lang::ENGLISH),
-            self.bibliography.region().copied().flatten(),
+            self.bibliography.lang.unwrap_or(Lang::ENGLISH),
+            self.bibliography.region.flatten(),
         );
 
         // Add hidden items for everything if we should print the whole
         // bibliography.
-        if self.bibliography.full(StyleChain::default()) {
+        if self.bibliography.full.get(StyleChain::default()) {
             for (_, entry) in database.iter() {
                 driver.citation(CitationRequest::new(
                     vec![CitationItem::new(entry, None, None, true, None)],
@@ -1071,25 +989,24 @@ fn apply_formatting(mut content: Content, format: &hayagriva::Formatting) -> Con
     match format.font_style {
         citationberg::FontStyle::Normal => {}
         citationberg::FontStyle::Italic => {
-            content = content.styled(TextElem::set_style(FontStyle::Italic));
+            content = content.set(TextElem::style, FontStyle::Italic);
         }
     }
 
     match format.font_variant {
         citationberg::FontVariant::Normal => {}
         citationberg::FontVariant::SmallCaps => {
-            content =
-                content.styled(TextElem::set_smallcaps(Some(Smallcaps::Minuscules)));
+            content = content.set(TextElem::smallcaps, Some(Smallcaps::Minuscules));
         }
     }
 
     match format.font_weight {
         citationberg::FontWeight::Normal => {}
         citationberg::FontWeight::Bold => {
-            content = content.styled(TextElem::set_delta(WeightDelta(300)));
+            content = content.set(TextElem::delta, WeightDelta(300));
         }
         citationberg::FontWeight::Light => {
-            content = content.styled(TextElem::set_delta(WeightDelta(-100)));
+            content = content.set(TextElem::delta, WeightDelta(-100));
         }
     }
 

crates/typst-library/src/model/cite.rs

@@ -3,8 +3,7 @@ use typst_syntax::Spanned;
 use crate::diag::{error, At, HintedString, SourceResult};
 use crate::engine::Engine;
 use crate::foundations::{
-    cast, elem, Cast, Content, Derived, Label, Packed, Show, Smart, StyleChain,
-    Synthesize,
+    cast, elem, Cast, Content, Derived, Label, Packed, Smart, StyleChain, Synthesize,
 };
 use crate::introspection::Locatable;
 use crate::model::bibliography::Works;
@@ -106,7 +105,6 @@ pub struct CiteElem {
         Some(Spanned { v: Smart::Auto, .. }) => Some(Smart::Auto),
         None => None,
     })]
-    #[borrowed]
     pub style: Smart<Derived<CslSource, CslStyle>>,
 
     /// The text language setting where the citation is.
@@ -123,8 +121,8 @@ pub struct CiteElem {
 impl Synthesize for Packed<CiteElem> {
     fn synthesize(&mut self, _: &mut Engine, styles: StyleChain) -> SourceResult<()> {
         let elem = self.as_mut();
-        elem.push_lang(TextElem::lang_in(styles));
-        elem.push_region(TextElem::region_in(styles));
+        elem.lang = Some(styles.get(TextElem::lang));
+        elem.region = Some(styles.get(TextElem::region));
         Ok(())
     }
 }
@@ -154,16 +152,15 @@ pub enum CitationForm {
 ///
 /// This is automatically created from adjacent citations during show rule
 /// application.
-#[elem(Locatable, Show)]
+#[elem(Locatable)]
 pub struct CiteGroup {
     /// The citations.
     #[required]
     pub children: Vec<Packed<CiteElem>>,
 }
 
-impl Show for Packed<CiteGroup> {
-    #[typst_macros::time(name = "cite", span = self.span())]
-    fn show(&self, engine: &mut Engine, _: StyleChain) -> SourceResult<Content> {
+impl Packed<CiteGroup> {
+    pub fn realize(&self, engine: &mut Engine) -> SourceResult<Content> {
         let location = self.location().unwrap();
         let span = self.span();
         Works::generate(engine)

crates/typst-library/src/model/document.rs

@@ -3,7 +3,7 @@ use ecow::EcoString;
 use crate::diag::{bail, HintedStrResult, SourceResult};
 use crate::engine::Engine;
 use crate::foundations::{
-    cast, elem, Args, Array, Construct, Content, Datetime, Fields, OneOrMultiple, Smart,
+    cast, elem, Args, Array, Construct, Content, Datetime, OneOrMultiple, Smart,
     StyleChain, Styles, Value,
 };
 
@@ -109,23 +109,26 @@ impl DocumentInfo {
     /// Document set rules are a bit special, so we need to do this manually.
     pub fn populate(&mut self, styles: &Styles) {
         let chain = StyleChain::new(styles);
-        let has = |field| styles.has::<DocumentElem>(field as _);
-        if has(<DocumentElem as Fields>::Enum::Title) {
-            self.title =
-                DocumentElem::title_in(chain).map(|content| content.plain_text());
+        if styles.has(DocumentElem::title) {
+            self.title = chain
+                .get_ref(DocumentElem::title)
+                .as_ref()
+                .map(|content| content.plain_text());
         }
-        if has(<DocumentElem as Fields>::Enum::Author) {
-            self.author = DocumentElem::author_in(chain).0;
+        if styles.has(DocumentElem::author) {
+            self.author = chain.get_cloned(DocumentElem::author).0;
         }
-        if has(<DocumentElem as Fields>::Enum::Description) {
-            self.description =
-                DocumentElem::description_in(chain).map(|content| content.plain_text());
+        if styles.has(DocumentElem::description) {
+            self.description = chain
+                .get_ref(DocumentElem::description)
+                .as_ref()
+                .map(|content| content.plain_text());
         }
-        if has(<DocumentElem as Fields>::Enum::Keywords) {
-            self.keywords = DocumentElem::keywords_in(chain).0;
+        if styles.has(DocumentElem::keywords) {
+            self.keywords = chain.get_cloned(DocumentElem::keywords).0;
         }
-        if has(<DocumentElem as Fields>::Enum::Date) {
-            self.date = DocumentElem::date_in(chain);
+        if styles.has(DocumentElem::date) {
+            self.date = chain.get(DocumentElem::date);
         }
     }
 }

crates/typst-library/src/model/emph.rs

@@ -1,10 +1,4 @@
-use crate::diag::SourceResult;
-use crate::engine::Engine;
-use crate::foundations::{
-    elem, Content, NativeElement, Packed, Show, StyleChain, TargetElem,
-};
-use crate::html::{tag, HtmlElem};
-use crate::text::{ItalicToggle, TextElem};
+use crate::foundations::{elem, Content};
 
 /// Emphasizes content by toggling italics.
 ///
@@ -29,24 +23,9 @@ use crate::text::{ItalicToggle, TextElem};
 /// This function also has dedicated syntax: To emphasize content, simply
 /// enclose it in underscores (`_`). Note that this only works at word
 /// boundaries. To emphasize part of a word, you have to use the function.
-#[elem(title = "Emphasis", keywords = ["italic"], Show)]
+#[elem(title = "Emphasis", keywords = ["italic"])]
 pub struct EmphElem {
     /// The content to emphasize.
     #[required]
     pub body: Content,
 }
-
-impl Show for Packed<EmphElem> {
-    #[typst_macros::time(name = "emph", span = self.span())]
-    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let body = self.body.clone();
-        Ok(if TargetElem::target_in(styles).is_html() {
-            HtmlElem::new(tag::em)
-                .with_body(Some(body))
-                .pack()
-                .spanned(self.span())
-        } else {
-            body.styled(TextElem::set_emph(ItalicToggle(true)))
-        })
-    }
-}

crates/typst-library/src/model/enum.rs

@@ -1,19 +1,11 @@
 use std::str::FromStr;
 
-use ecow::eco_format;
 use smallvec::SmallVec;
 
-use crate::diag::{bail, SourceResult};
-use crate::engine::Engine;
-use crate::foundations::{
-    cast, elem, scope, Array, Content, NativeElement, Packed, Show, Smart, StyleChain,
-    Styles, TargetElem,
-};
-use crate::html::{attr, tag, HtmlElem};
-use crate::layout::{Alignment, BlockElem, Em, HAlignment, Length, VAlignment, VElem};
-use crate::model::{
-    ListItemLike, ListLike, Numbering, NumberingPattern, ParElem, ParbreakElem,
-};
+use crate::diag::bail;
+use crate::foundations::{cast, elem, scope, Array, Content, Packed, Smart, Styles};
+use crate::layout::{Alignment, Em, HAlignment, Length, VAlignment};
+use crate::model::{ListItemLike, ListLike, Numbering, NumberingPattern};
 
 /// A numbered list.
 ///
@@ -71,7 +63,7 @@ use crate::model::{
 /// Enumeration items can contain multiple paragraphs and other block-level
 /// content. All content that is indented more than an item's marker becomes
 /// part of that item.
-#[elem(scope, title = "Numbered List", Show)]
+#[elem(scope, title = "Numbered List")]
 pub struct EnumElem {
     /// Defines the default [spacing]($enum.spacing) of the enumeration. If it
     /// is `{false}`, the items are spaced apart with
@@ -117,7 +109,6 @@ pub struct EnumElem {
     /// + Numbering!
     /// ```
     #[default(Numbering::Pattern(NumberingPattern::from_str("1.").unwrap()))]
-    #[borrowed]
     pub numbering: Numbering,
 
     /// Which number to start the enumeration with.
@@ -157,11 +148,9 @@ pub struct EnumElem {
     pub reversed: bool,
 
     /// The indentation of each item.
-    #[resolve]
     pub indent: Length,
 
     /// The space between the numbering and the body of each item.
-    #[resolve]
     #[default(Em::new(0.5).into())]
     pub body_indent: Length,
 
@@ -226,50 +215,6 @@ impl EnumElem {
     type EnumItem;
 }
 
-impl Show for Packed<EnumElem> {
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let tight = self.tight(styles);
-
-        if TargetElem::target_in(styles).is_html() {
-            let mut elem = HtmlElem::new(tag::ol);
-            if self.reversed(styles) {
-                elem = elem.with_attr(attr::reversed, "reversed");
-            }
-            if let Some(n) = self.start(styles).custom() {
-                elem = elem.with_attr(attr::start, eco_format!("{n}"));
-            }
-            let body = Content::sequence(self.children.iter().map(|item| {
-                let mut li = HtmlElem::new(tag::li);
-                if let Some(nr) = item.number(styles) {
-                    li = li.with_attr(attr::value, eco_format!("{nr}"));
-                }
-                // Text in wide enums shall always turn into paragraphs.
-                let mut body = item.body.clone();
-                if !tight {
-                    body += ParbreakElem::shared();
-                }
-                li.with_body(Some(body)).pack().spanned(item.span())
-            }));
-            return Ok(elem.with_body(Some(body)).pack().spanned(self.span()));
-        }
-
-        let mut realized =
-            BlockElem::multi_layouter(self.clone(), engine.routines.layout_enum)
-                .pack()
-                .spanned(self.span());
-
-        if tight {
-            let spacing = self
-                .spacing(styles)
-                .unwrap_or_else(|| ParElem::leading_in(styles).into());
-            let v = VElem::new(spacing.into()).with_weak(true).with_attach(true).pack();
-            realized = v + realized;
-        }
-
-        Ok(realized)
-    }
-}
-
 /// An enumeration item.
 #[elem(name = "item", title = "Numbered List Item")]
 pub struct EnumItem {

crates/typst-library/src/model/figure.rs

@@ -9,19 +9,16 @@ use crate::diag::{bail, SourceResult};
 use crate::engine::Engine;
 use crate::foundations::{
     cast, elem, scope, select_where, Content, Element, NativeElement, Packed, Selector,
-    Show, ShowSet, Smart, StyleChain, Styles, Synthesize, TargetElem,
+    ShowSet, Smart, StyleChain, Styles, Synthesize,
 };
-use crate::html::{tag, HtmlElem};
 use crate::introspection::{
     Count, Counter, CounterKey, CounterUpdate, Locatable, Location,
 };
 use crate::layout::{
-    AlignElem, Alignment, BlockBody, BlockElem, Em, HAlignment, Length, OuterVAlignment,
-    PlaceElem, PlacementScope, VAlignment, VElem,
-};
-use crate::model::{
-    Numbering, NumberingPattern, Outlinable, ParbreakElem, Refable, Supplement,
+    AlignElem, Alignment, BlockElem, Em, Length, OuterVAlignment, PlacementScope,
+    VAlignment,
 };
+use crate::model::{Numbering, NumberingPattern, Outlinable, Refable, Supplement};
 use crate::text::{Lang, Region, TextElem};
 use crate::visualize::ImageElem;
 
@@ -104,7 +101,7 @@ use crate::visualize::ImageElem;
 ///   caption: [I'm up here],
 /// )
 /// ```
-#[elem(scope, Locatable, Synthesize, Count, Show, ShowSet, Refable, Outlinable)]
+#[elem(scope, Locatable, Synthesize, Count, ShowSet, Refable, Outlinable)]
 pub struct FigureElem {
     /// The content of the figure. Often, an [image].
     #[required]
@@ -161,7 +158,6 @@ pub struct FigureElem {
     pub scope: PlacementScope,
 
     /// The figure's caption.
-    #[borrowed]
     pub caption: Option<Packed<FigureCaption>>,
 
     /// The kind of figure this is.
@@ -214,13 +210,11 @@ pub struct FigureElem {
     ///   kind: "foo",
     /// )
     /// ```
-    #[borrowed]
     pub supplement: Smart<Option<Supplement>>,
 
     /// How to number the figure. Accepts a
     /// [numbering pattern or function]($numbering).
     #[default(Some(NumberingPattern::from_str("1").unwrap().into()))]
-    #[borrowed]
     pub numbering: Option<Numbering>,
 
     /// The vertical gap between the body and caption.
@@ -259,25 +253,25 @@ impl Synthesize for Packed<FigureElem> {
         let span = self.span();
         let location = self.location();
         let elem = self.as_mut();
-        let numbering = elem.numbering(styles);
+        let numbering = elem.numbering.get_ref(styles);
 
         // Determine the figure's kind.
-        let kind = elem.kind(styles).unwrap_or_else(|| {
+        let kind = elem.kind.get_cloned(styles).unwrap_or_else(|| {
             elem.body
                 .query_first(&Selector::can::<dyn Figurable>())
                 .map(|elem| FigureKind::Elem(elem.func()))
-                .unwrap_or_else(|| FigureKind::Elem(ImageElem::elem()))
+                .unwrap_or_else(|| FigureKind::Elem(ImageElem::ELEM))
         });
 
         // Resolve the supplement.
-        let supplement = match elem.supplement(styles).as_ref() {
+        let supplement = match elem.supplement.get_ref(styles).as_ref() {
             Smart::Auto => {
                 // Default to the local name for the kind, if available.
                 let name = match &kind {
                     FigureKind::Elem(func) => func
                         .local_name(
-                            TextElem::lang_in(styles),
-                            TextElem::region_in(styles),
+                            styles.get(TextElem::lang),
+                            styles.get(TextElem::region),
                         )
                         .map(TextElem::packed),
                     FigureKind::Name(_) => None,
@@ -307,95 +301,37 @@ impl Synthesize for Packed<FigureElem> {
 
         // Construct the figure's counter.
         let counter = Counter::new(CounterKey::Selector(
-            select_where!(FigureElem, Kind => kind.clone()),
+            select_where!(FigureElem, kind => kind.clone()),
         ));
 
         // Fill the figure's caption.
-        let mut caption = elem.caption(styles).clone();
+        let mut caption = elem.caption.get_cloned(styles);
         if let Some(caption) = &mut caption {
             caption.synthesize(engine, styles)?;
-            caption.push_kind(kind.clone());
-            caption.push_supplement(supplement.clone());
-            caption.push_numbering(numbering.clone());
-            caption.push_counter(Some(counter.clone()));
-            caption.push_figure_location(location);
+            caption.kind = Some(kind.clone());
+            caption.supplement = Some(supplement.clone());
+            caption.numbering = Some(numbering.clone());
+            caption.counter = Some(Some(counter.clone()));
+            caption.figure_location = Some(location);
         }
 
-        elem.push_kind(Smart::Custom(kind));
-        elem.push_supplement(Smart::Custom(supplement.map(Supplement::Content)));
-        elem.push_counter(Some(counter));
-        elem.push_caption(caption);
+        elem.kind.set(Smart::Custom(kind));
+        elem.supplement
+            .set(Smart::Custom(supplement.map(Supplement::Content)));
+        elem.counter = Some(Some(counter));
+        elem.caption.set(caption);
 
         Ok(())
     }
 }
 
-impl Show for Packed<FigureElem> {
-    #[typst_macros::time(name = "figure", span = self.span())]
-    fn show(&self, _: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let span = self.span();
-        let target = TargetElem::target_in(styles);
-        let mut realized = self.body.clone();
-
-        // Build the caption, if any.
-        if let Some(caption) = self.caption(styles).clone() {
-            let (first, second) = match caption.position(styles) {
-                OuterVAlignment::Top => (caption.pack(), realized),
-                OuterVAlignment::Bottom => (realized, caption.pack()),
-            };
-            let mut seq = Vec::with_capacity(3);
-            seq.push(first);
-            if !target.is_html() {
-                let v = VElem::new(self.gap(styles).into()).with_weak(true);
-                seq.push(v.pack().spanned(span))
-            }
-            seq.push(second);
-            realized = Content::sequence(seq)
-        }
-
-        // Ensure that the body is considered a paragraph.
-        realized += ParbreakElem::shared().clone().spanned(span);
-
-        if target.is_html() {
-            return Ok(HtmlElem::new(tag::figure)
-                .with_body(Some(realized))
-                .pack()
-                .spanned(span));
-        }
-
-        // Wrap the contents in a block.
-        realized = BlockElem::new()
-            .with_body(Some(BlockBody::Content(realized)))
-            .pack()
-            .spanned(span);
-
-        // Wrap in a float.
-        if let Some(align) = self.placement(styles) {
-            realized = PlaceElem::new(realized)
-                .with_alignment(align.map(|align| HAlignment::Center + align))
-                .with_scope(self.scope(styles))
-                .with_float(true)
-                .pack()
-                .spanned(span);
-        } else if self.scope(styles) == PlacementScope::Parent {
-            bail!(
-                span,
-                "parent-scoped placement is only available for floating figures";
-                hint: "you can enable floating placement with `figure(placement: auto, ..)`"
-            );
-        }
-
-        Ok(realized)
-    }
-}
-
 impl ShowSet for Packed<FigureElem> {
     fn show_set(&self, _: StyleChain) -> Styles {
         // Still allows breakable figures with
         // `show figure: set block(breakable: true)`.
         let mut map = Styles::new();
-        map.set(BlockElem::set_breakable(false));
-        map.set(AlignElem::set_alignment(Alignment::CENTER));
+        map.set(BlockElem::breakable, false);
+        map.set(AlignElem::alignment, Alignment::CENTER);
         map
     }
 }
@@ -413,29 +349,28 @@ impl Count for Packed<FigureElem> {
 impl Refable for Packed<FigureElem> {
     fn supplement(&self) -> Content {
         // After synthesis, this should always be custom content.
-        match (**self).supplement(StyleChain::default()).as_ref() {
-            Smart::Custom(Some(Supplement::Content(content))) => content.clone(),
+        match self.supplement.get_cloned(StyleChain::default()) {
+            Smart::Custom(Some(Supplement::Content(content))) => content,
             _ => Content::empty(),
         }
     }
 
     fn counter(&self) -> Counter {
-        (**self)
-            .counter()
-            .cloned()
+        self.counter
+            .clone()
             .flatten()
-            .unwrap_or_else(|| Counter::of(FigureElem::elem()))
+            .unwrap_or_else(|| Counter::of(FigureElem::ELEM))
     }
 
     fn numbering(&self) -> Option<&Numbering> {
-        (**self).numbering(StyleChain::default()).as_ref()
+        self.numbering.get_ref(StyleChain::default()).as_ref()
     }
 }
 
 impl Outlinable for Packed<FigureElem> {
     fn outlined(&self) -> bool {
-        (**self).outlined(StyleChain::default())
-            && (self.caption(StyleChain::default()).is_some()
+        self.outlined.get(StyleChain::default())
+            && (self.caption.get_ref(StyleChain::default()).is_some()
                 || self.numbering().is_some())
     }
 
@@ -449,7 +384,8 @@ impl Outlinable for Packed<FigureElem> {
     }
 
     fn body(&self) -> Content {
-        self.caption(StyleChain::default())
+        self.caption
+            .get_ref(StyleChain::default())
             .as_ref()
             .map(|caption| caption.body.clone())
             .unwrap_or_default()
@@ -473,7 +409,7 @@ impl Outlinable for Packed<FigureElem> {
 ///   caption: [A rectangle],
 /// )
 /// ```
-#[elem(name = "caption", Synthesize, Show)]
+#[elem(name = "caption", Synthesize)]
 pub struct FigureCaption {
     /// The caption's position in the figure. Either `{top}` or `{bottom}`.
     ///
@@ -561,6 +497,35 @@ pub struct FigureCaption {
 }
 
 impl FigureCaption {
+    /// Realizes the textual caption content.
+    pub fn realize(
+        &self,
+        engine: &mut Engine,
+        styles: StyleChain,
+    ) -> SourceResult<Content> {
+        let mut realized = self.body.clone();
+
+        if let (
+            Some(Some(mut supplement)),
+            Some(Some(numbering)),
+            Some(Some(counter)),
+            Some(Some(location)),
+        ) = (
+            self.supplement.clone(),
+            &self.numbering,
+            &self.counter,
+            &self.figure_location,
+        ) {
+            let numbers = counter.display_at_loc(engine, *location, styles, numbering)?;
+            if !supplement.is_empty() {
+                supplement += TextElem::packed('\u{a0}');
+            }
+            realized = supplement + numbers + self.get_separator(styles) + realized;
+        }
+
+        Ok(realized)
+    }
+
     /// Gets the default separator in the given language and (optionally)
     /// region.
     fn local_separator(lang: Lang, _: Option<Region>) -> &'static str {
@@ -573,10 +538,10 @@ impl FigureCaption {
     }
 
     fn get_separator(&self, styles: StyleChain) -> Content {
-        self.separator(styles).unwrap_or_else(|| {
+        self.separator.get_cloned(styles).unwrap_or_else(|| {
             TextElem::packed(Self::local_separator(
-                TextElem::lang_in(styles),
-                TextElem::region_in(styles),
+                styles.get(TextElem::lang),
+                styles.get(TextElem::region),
             ))
         })
     }
@@ -585,48 +550,11 @@ impl FigureCaption {
 impl Synthesize for Packed<FigureCaption> {
     fn synthesize(&mut self, _: &mut Engine, styles: StyleChain) -> SourceResult<()> {
         let elem = self.as_mut();
-        elem.push_separator(Smart::Custom(elem.get_separator(styles)));
+        elem.separator.set(Smart::Custom(elem.get_separator(styles)));
         Ok(())
     }
 }
 
-impl Show for Packed<FigureCaption> {
-    #[typst_macros::time(name = "figure.caption", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let mut realized = self.body.clone();
-
-        if let (
-            Some(Some(mut supplement)),
-            Some(Some(numbering)),
-            Some(Some(counter)),
-            Some(Some(location)),
-        ) = (
-            self.supplement().cloned(),
-            self.numbering(),
-            self.counter(),
-            self.figure_location(),
-        ) {
-            let numbers = counter.display_at_loc(engine, *location, styles, numbering)?;
-            if !supplement.is_empty() {
-                supplement += TextElem::packed('\u{a0}');
-            }
-            realized = supplement + numbers + self.get_separator(styles) + realized;
-        }
-
-        Ok(if TargetElem::target_in(styles).is_html() {
-            HtmlElem::new(tag::figcaption)
-                .with_body(Some(realized))
-                .pack()
-                .spanned(self.span())
-        } else {
-            BlockElem::new()
-                .with_body(Some(BlockBody::Content(realized)))
-                .pack()
-                .spanned(self.span())
-        })
-    }
-}
-
 cast! {
     FigureCaption,
     v: Content => v.unpack::<Self>().unwrap_or_else(Self::new),

crates/typst-library/src/model/footnote.rs

@@ -3,16 +3,16 @@ use std::str::FromStr;
 
 use typst_utils::NonZeroExt;
 
-use crate::diag::{bail, At, SourceResult, StrResult};
+use crate::diag::{bail, StrResult};
 use crate::engine::Engine;
 use crate::foundations::{
-    cast, elem, scope, Content, Label, NativeElement, Packed, Show, ShowSet, Smart,
-    StyleChain, Styles,
+    cast, elem, scope, Content, Label, NativeElement, Packed, ShowSet, Smart, StyleChain,
+    Styles,
 };
-use crate::introspection::{Count, Counter, CounterUpdate, Locatable, Location};
-use crate::layout::{Abs, Em, HElem, Length, Ratio};
-use crate::model::{Destination, Numbering, NumberingPattern, ParElem};
-use crate::text::{SuperElem, TextElem, TextSize};
+use crate::introspection::{Count, CounterUpdate, Locatable, Location};
+use crate::layout::{Abs, Em, Length, Ratio};
+use crate::model::{Numbering, NumberingPattern, ParElem};
+use crate::text::{TextElem, TextSize};
 use crate::visualize::{LineElem, Stroke};
 
 /// A footnote.
@@ -51,7 +51,7 @@ use crate::visualize::{LineElem, Stroke};
 /// apply to the footnote's content. See [here][issue] for more information.
 ///
 /// [issue]: https://github.com/typst/typst/issues/1467#issuecomment-1588799440
-#[elem(scope, Locatable, Show, Count)]
+#[elem(scope, Locatable, Count)]
 pub struct FootnoteElem {
     /// How to number footnotes.
     ///
@@ -67,7 +67,6 @@ pub struct FootnoteElem {
     /// #footnote[Star],
     /// #footnote[Dagger]
     /// ```
-    #[borrowed]
     #[default(Numbering::Pattern(NumberingPattern::from_str("1").unwrap()))]
     pub numbering: Numbering,
 
@@ -136,21 +135,6 @@ impl Packed<FootnoteElem> {
     }
 }
 
-impl Show for Packed<FootnoteElem> {
-    #[typst_macros::time(name = "footnote", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let span = self.span();
-        let loc = self.declaration_location(engine).at(span)?;
-        let numbering = self.numbering(styles);
-        let counter = Counter::of(FootnoteElem::elem());
-        let num = counter.display_at_loc(engine, loc, styles, numbering)?;
-        let sup = SuperElem::new(num).pack().spanned(span);
-        let loc = loc.variant(1);
-        // Add zero-width weak spacing to make the footnote "sticky".
-        Ok(HElem::hole().pack() + sup.linked(Destination::Location(loc)))
-    }
-}
-
 impl Count for Packed<FootnoteElem> {
     fn update(&self) -> Option<CounterUpdate> {
         (!self.is_ref()).then(|| CounterUpdate::Step(NonZeroUsize::ONE))
@@ -192,7 +176,7 @@ cast! {
 /// page run is a sequence of pages without an explicit pagebreak in between).
 /// For this reason, set and show rules for footnote entries should be defined
 /// before any page content, typically at the very start of the document.
-#[elem(name = "entry", title = "Footnote Entry", Show, ShowSet)]
+#[elem(name = "entry", title = "Footnote Entry", ShowSet)]
 pub struct FootnoteEntry {
     /// The footnote for this entry. Its location can be used to determine
     /// the footnote counter state.
@@ -248,7 +232,6 @@ pub struct FootnoteEntry {
     /// ]
     /// ```
     #[default(Em::new(1.0).into())]
-    #[resolve]
     pub clearance: Length,
 
     /// The gap between footnote entries.
@@ -261,7 +244,6 @@ pub struct FootnoteEntry {
     /// #footnote[Apart]
     /// ```
     #[default(Em::new(0.5).into())]
-    #[resolve]
     pub gap: Length,
 
     /// The indent of each footnote entry.
@@ -277,42 +259,11 @@ pub struct FootnoteEntry {
     pub indent: Length,
 }
 
-impl Show for Packed<FootnoteEntry> {
-    #[typst_macros::time(name = "footnote.entry", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let span = self.span();
-        let number_gap = Em::new(0.05);
-        let default = StyleChain::default();
-        let numbering = self.note.numbering(default);
-        let counter = Counter::of(FootnoteElem::elem());
-        let Some(loc) = self.note.location() else {
-            bail!(
-                span, "footnote entry must have a location";
-                hint: "try using a query or a show rule to customize the footnote instead"
-            );
-        };
-
-        let num = counter.display_at_loc(engine, loc, styles, numbering)?;
-        let sup = SuperElem::new(num)
-            .pack()
-            .spanned(span)
-            .linked(Destination::Location(loc))
-            .located(loc.variant(1));
-
-        Ok(Content::sequence([
-            HElem::new(self.indent(styles).into()).pack(),
-            sup,
-            HElem::new(number_gap.into()).with_weak(true).pack(),
-            self.note.body_content().unwrap().clone(),
-        ]))
-    }
-}
-
 impl ShowSet for Packed<FootnoteEntry> {
     fn show_set(&self, _: StyleChain) -> Styles {
         let mut out = Styles::new();
-        out.set(ParElem::set_leading(Em::new(0.5).into()));
-        out.set(TextElem::set_size(TextSize(Em::new(0.85).into())));
+        out.set(ParElem::leading, Em::new(0.5).into());
+        out.set(TextElem::size, TextSize(Em::new(0.85).into()));
         out
     }
 }

crates/typst-library/src/model/heading.rs

@@ -1,21 +1,16 @@
 use std::num::NonZeroUsize;
 
-use ecow::eco_format;
-use typst_utils::{Get, NonZeroExt};
+use typst_utils::NonZeroExt;
 
-use crate::diag::{warning, SourceResult};
+use crate::diag::SourceResult;
 use crate::engine::Engine;
 use crate::foundations::{
-    elem, Content, NativeElement, Packed, Resolve, Show, ShowSet, Smart, StyleChain,
-    Styles, Synthesize, TargetElem,
+    elem, Content, NativeElement, Packed, ShowSet, Smart, StyleChain, Styles, Synthesize,
 };
-use crate::html::{attr, tag, HtmlElem};
-use crate::introspection::{
-    Count, Counter, CounterUpdate, Locatable, Locator, LocatorLink,
-};
-use crate::layout::{Abs, Axes, BlockBody, BlockElem, Em, HElem, Length, Region, Sides};
+use crate::introspection::{Count, Counter, CounterUpdate, Locatable};
+use crate::layout::{BlockElem, Em, Length};
 use crate::model::{Numbering, Outlinable, Refable, Supplement};
-use crate::text::{FontWeight, LocalName, SpaceElem, TextElem, TextSize};
+use crate::text::{FontWeight, LocalName, TextElem, TextSize};
 
 /// A section heading.
 ///
@@ -49,7 +44,7 @@ use crate::text::{FontWeight, LocalName, SpaceElem, TextElem, TextSize};
 /// one or multiple equals signs, followed by a space. The number of equals
 /// signs determines the heading's logical nesting depth. The `{offset}` field
 /// can be set to configure the starting depth.
-#[elem(Locatable, Synthesize, Count, Show, ShowSet, LocalName, Refable, Outlinable)]
+#[elem(Locatable, Synthesize, Count, ShowSet, LocalName, Refable, Outlinable)]
 pub struct HeadingElem {
     /// The absolute nesting depth of the heading, starting from one. If set
     /// to `{auto}`, it is computed from `{offset + depth}`.
@@ -106,7 +101,6 @@ pub struct HeadingElem {
     /// == A subsection
     /// === A sub-subsection
     /// ```
-    #[borrowed]
     pub numbering: Option<Numbering>,
 
     /// A supplement for the heading.
@@ -187,8 +181,8 @@ pub struct HeadingElem {
 
 impl HeadingElem {
     pub fn resolve_level(&self, styles: StyleChain) -> NonZeroUsize {
-        self.level(styles).unwrap_or_else(|| {
-            NonZeroUsize::new(self.offset(styles) + self.depth(styles).get())
+        self.level.get(styles).unwrap_or_else(|| {
+            NonZeroUsize::new(self.offset.get(styles) + self.depth.get(styles).get())
                 .expect("overflow to 0 on NoneZeroUsize + usize")
         })
     }
@@ -200,7 +194,7 @@ impl Synthesize for Packed<HeadingElem> {
         engine: &mut Engine,
         styles: StyleChain,
     ) -> SourceResult<()> {
-        let supplement = match (**self).supplement(styles) {
+        let supplement = match self.supplement.get_ref(styles) {
             Smart::Auto => TextElem::packed(Self::local_name_in(styles)),
             Smart::Custom(None) => Content::empty(),
             Smart::Custom(Some(supplement)) => {
@@ -209,105 +203,16 @@ impl Synthesize for Packed<HeadingElem> {
         };
 
         let elem = self.as_mut();
-        elem.push_level(Smart::Custom(elem.resolve_level(styles)));
-        elem.push_supplement(Smart::Custom(Some(Supplement::Content(supplement))));
+        elem.level.set(Smart::Custom(elem.resolve_level(styles)));
+        elem.supplement
+            .set(Smart::Custom(Some(Supplement::Content(supplement))));
         Ok(())
     }
 }
 
-impl Show for Packed<HeadingElem> {
-    #[typst_macros::time(name = "heading", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let html = TargetElem::target_in(styles).is_html();
-
-        const SPACING_TO_NUMBERING: Em = Em::new(0.3);
-
-        let span = self.span();
-        let mut realized = self.body.clone();
-
-        let hanging_indent = self.hanging_indent(styles);
-        let mut indent = match hanging_indent {
-            Smart::Custom(length) => length.resolve(styles),
-            Smart::Auto => Abs::zero(),
-        };
-
-        if let Some(numbering) = (**self).numbering(styles).as_ref() {
-            let location = self.location().unwrap();
-            let numbering = Counter::of(HeadingElem::elem())
-                .display_at_loc(engine, location, styles, numbering)?
-                .spanned(span);
-
-            if hanging_indent.is_auto() && !html {
-                let pod = Region::new(Axes::splat(Abs::inf()), Axes::splat(false));
-
-                // We don't have a locator for the numbering here, so we just
-                // use the measurement infrastructure for now.
-                let link = LocatorLink::measure(location);
-                let size = (engine.routines.layout_frame)(
-                    engine,
-                    &numbering,
-                    Locator::link(&link),
-                    styles,
-                    pod,
-                )?
-                .size();
-
-                indent = size.x + SPACING_TO_NUMBERING.resolve(styles);
-            }
-
-            let spacing = if html {
-                SpaceElem::shared().clone()
-            } else {
-                HElem::new(SPACING_TO_NUMBERING.into()).with_weak(true).pack()
-            };
-
-            realized = numbering + spacing + realized;
-        }
-
-        Ok(if html {
-            // HTML's h1 is closer to a title element. There should only be one.
-            // Meanwhile, a level 1 Typst heading is a section heading. For this
-            // reason, levels are offset by one: A Typst level 1 heading becomes
-            // a `<h2>`.
-            let level = self.resolve_level(styles).get();
-            if level >= 6 {
-                engine.sink.warn(warning!(span,
-                    "heading of level {} was transformed to \
-                    <div role=\"heading\" aria-level=\"{}\">, which is not \
-                    supported by all assistive technology",
-                    level, level + 1;
-                    hint: "HTML only supports <h1> to <h6>, not <h{}>", level + 1;
-                    hint: "you may want to restructure your document so that \
-                          it doesn't contain deep headings"));
-                HtmlElem::new(tag::div)
-                    .with_body(Some(realized))
-                    .with_attr(attr::role, "heading")
-                    .with_attr(attr::aria_level, eco_format!("{}", level + 1))
-                    .pack()
-                    .spanned(span)
-            } else {
-                let t = [tag::h2, tag::h3, tag::h4, tag::h5, tag::h6][level - 1];
-                HtmlElem::new(t).with_body(Some(realized)).pack().spanned(span)
-            }
-        } else {
-            let block = if indent != Abs::zero() {
-                let body = HElem::new((-indent).into()).pack() + realized;
-                let inset = Sides::default()
-                    .with(TextElem::dir_in(styles).start(), Some(indent.into()));
-                BlockElem::new()
-                    .with_body(Some(BlockBody::Content(body)))
-                    .with_inset(inset)
-            } else {
-                BlockElem::new().with_body(Some(BlockBody::Content(realized)))
-            };
-            block.pack().spanned(span)
-        })
-    }
-}
-
 impl ShowSet for Packed<HeadingElem> {
     fn show_set(&self, styles: StyleChain) -> Styles {
-        let level = (**self).resolve_level(styles).get();
+        let level = self.resolve_level(styles).get();
         let scale = match level {
             1 => 1.4,
             2 => 1.2,
@@ -319,49 +224,49 @@ impl ShowSet for Packed<HeadingElem> {
         let below = Em::new(0.75) / scale;
 
         let mut out = Styles::new();
-        out.set(TextElem::set_size(TextSize(size.into())));
-        out.set(TextElem::set_weight(FontWeight::BOLD));
-        out.set(BlockElem::set_above(Smart::Custom(above.into())));
-        out.set(BlockElem::set_below(Smart::Custom(below.into())));
-        out.set(BlockElem::set_sticky(true));
+        out.set(TextElem::size, TextSize(size.into()));
+        out.set(TextElem::weight, FontWeight::BOLD);
+        out.set(BlockElem::above, Smart::Custom(above.into()));
+        out.set(BlockElem::below, Smart::Custom(below.into()));
+        out.set(BlockElem::sticky, true);
         out
     }
 }
 
 impl Count for Packed<HeadingElem> {
     fn update(&self) -> Option<CounterUpdate> {
-        (**self)
-            .numbering(StyleChain::default())
+        self.numbering
+            .get_ref(StyleChain::default())
             .is_some()
-            .then(|| CounterUpdate::Step((**self).resolve_level(StyleChain::default())))
+            .then(|| CounterUpdate::Step(self.resolve_level(StyleChain::default())))
     }
 }
 
 impl Refable for Packed<HeadingElem> {
     fn supplement(&self) -> Content {
         // After synthesis, this should always be custom content.
-        match (**self).supplement(StyleChain::default()) {
+        match self.supplement.get_cloned(StyleChain::default()) {
             Smart::Custom(Some(Supplement::Content(content))) => content,
             _ => Content::empty(),
         }
     }
 
     fn counter(&self) -> Counter {
-        Counter::of(HeadingElem::elem())
+        Counter::of(HeadingElem::ELEM)
     }
 
     fn numbering(&self) -> Option<&Numbering> {
-        (**self).numbering(StyleChain::default()).as_ref()
+        self.numbering.get_ref(StyleChain::default()).as_ref()
     }
 }
 
 impl Outlinable for Packed<HeadingElem> {
     fn outlined(&self) -> bool {
-        (**self).outlined(StyleChain::default())
+        self.outlined.get(StyleChain::default())
     }
 
     fn level(&self) -> NonZeroUsize {
-        (**self).resolve_level(StyleChain::default())
+        self.resolve_level(StyleChain::default())
     }
 
     fn prefix(&self, numbers: Content) -> Content {

crates/typst-library/src/model/link.rs

@@ -2,13 +2,10 @@ use std::ops::Deref;
 
 use ecow::{eco_format, EcoString};
 
-use crate::diag::{bail, warning, At, SourceResult, StrResult};
-use crate::engine::Engine;
+use crate::diag::{bail, StrResult};
 use crate::foundations::{
-    cast, elem, Content, Label, NativeElement, Packed, Repr, Show, ShowSet, Smart,
-    StyleChain, Styles, TargetElem,
+    cast, elem, Content, Label, Packed, Repr, ShowSet, Smart, StyleChain, Styles,
 };
-use crate::html::{attr, tag, HtmlElem};
 use crate::introspection::Location;
 use crate::layout::Position;
 use crate::text::TextElem;
@@ -38,7 +35,7 @@ use crate::text::TextElem;
 /// # Syntax
 /// This function also has dedicated syntax: Text that starts with `http://` or
 /// `https://` is automatically turned into a link.
-#[elem(Show)]
+#[elem]
 pub struct LinkElem {
     /// The destination the link points to.
     ///
@@ -103,42 +100,10 @@ impl LinkElem {
     }
 }
 
-impl Show for Packed<LinkElem> {
-    #[typst_macros::time(name = "link", span = self.span())]
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let body = self.body.clone();
-
-        Ok(if TargetElem::target_in(styles).is_html() {
-            if let LinkTarget::Dest(Destination::Url(url)) = &self.dest {
-                HtmlElem::new(tag::a)
-                    .with_attr(attr::href, url.clone().into_inner())
-                    .with_body(Some(body))
-                    .pack()
-                    .spanned(self.span())
-            } else {
-                engine.sink.warn(warning!(
-                    self.span(),
-                    "non-URL links are not yet supported by HTML export"
-                ));
-                body
-            }
-        } else {
-            match &self.dest {
-                LinkTarget::Dest(dest) => body.linked(dest.clone()),
-                LinkTarget::Label(label) => {
-                    let elem = engine.introspector.query_label(*label).at(self.span())?;
-                    let dest = Destination::Location(elem.location().unwrap());
-                    body.clone().linked(dest)
-                }
-            }
-        })
-    }
-}
-
 impl ShowSet for Packed<LinkElem> {
     fn show_set(&self, _: StyleChain) -> Styles {
         let mut out = Styles::new();
-        out.set(TextElem::set_hyphenate(Smart::Custom(false)));
+        out.set(TextElem::hyphenate, Smart::Custom(false));
         out
     }
 }

crates/typst-library/src/model/list.rs

@@ -3,12 +3,10 @@ use comemo::Track;
 use crate::diag::{bail, SourceResult};
 use crate::engine::Engine;
 use crate::foundations::{
-    cast, elem, scope, Array, Content, Context, Depth, Func, NativeElement, Packed, Show,
-    Smart, StyleChain, Styles, TargetElem, Value,
+    cast, elem, scope, Array, Content, Context, Depth, Func, NativeElement, Packed,
+    Smart, StyleChain, Styles, Value,
 };
-use crate::html::{tag, HtmlElem};
-use crate::layout::{BlockElem, Em, Length, VElem};
-use crate::model::{ParElem, ParbreakElem};
+use crate::layout::{Em, Length};
 use crate::text::TextElem;
 
 /// A bullet list.
@@ -42,7 +40,7 @@ use crate::text::TextElem;
 /// followed by a space to create a list item. A list item can contain multiple
 /// paragraphs and other block-level content. All content that is indented
 /// more than an item's marker becomes part of that item.
-#[elem(scope, title = "Bullet List", Show)]
+#[elem(scope, title = "Bullet List")]
 pub struct ListElem {
     /// Defines the default [spacing]($list.spacing) of the list. If it is
     /// `{false}`, the items are spaced apart with
@@ -86,7 +84,6 @@ pub struct ListElem {
     ///   - Items
     /// - Items
     /// ```
-    #[borrowed]
     #[default(ListMarker::Content(vec![
         // These are all available in the default font, vertically centered, and
         // roughly of the same size (with the last one having slightly lower
@@ -98,11 +95,9 @@ pub struct ListElem {
     pub marker: ListMarker,
 
     /// The indent of each item.
-    #[resolve]
     pub indent: Length,
 
     /// The spacing between the marker and the body of each item.
-    #[resolve]
     #[default(Em::new(0.5).into())]
     pub body_indent: Length,
 
@@ -139,44 +134,6 @@ impl ListElem {
     type ListItem;
 }
 
-impl Show for Packed<ListElem> {
-    fn show(&self, engine: &mut Engine, styles: StyleChain) -> SourceResult<Content> {
-        let tight = self.tight(styles);
-
-        if TargetElem::target_in(styles).is_html() {
-            return Ok(HtmlElem::new(tag::ul)
-                .with_body(Some(Content::sequence(self.children.iter().map(|item| {
-                    // Text in wide lists shall always turn into paragraphs.
-                    let mut body = item.body.clone();
-                    if !tight {
-                        body += ParbreakElem::shared();
-                    }
-                    HtmlElem::new(tag::li)
-                        .with_body(Some(body))
-                        .pack()
-                        .spanned(item.span())
-                }))))
-                .pack()
-                .spanned(self.span()));
-        }
-
-        let mut realized =
-            BlockElem::multi_layouter(self.clone(), engine.routines.layout_list)
-                .pack()
-                .spanned(self.span());
-
-        if tight {
-            let spacing = self
-                .spacing(styles)
-                .unwrap_or_else(|| ParElem::leading_in(styles).into());
-            let v = VElem::new(spacing.into()).with_weak(true).with_attach(true).pack();
-            realized = v + realized;
-        }
-
-        Ok(realized)
-    }
-}
-
 /// A bullet list item.
 #[elem(name = "item", title = "Bullet List Item")]
 pub struct ListItem {