Locatability and synthesis improvements

library/src/compute/data.rs

@@ -27,7 +27,7 @@ pub fn read(
     let Spanned { v: path, span } = path;
     let path = vm.locate(&path).at(span)?;
     let data = vm.world().file(&path).at(span)?;
-    let text = String::from_utf8(data.to_vec())
+    let text = std::str::from_utf8(&data)
         .map_err(|_| "file is not valid utf-8")
         .at(span)?;
     Value::Str(text.into())

library/src/meta/figure.rs

@@ -23,7 +23,7 @@ use crate::text::TextNode;
 ///
 /// Display: Figure
 /// Category: meta
-#[node(Synthesize, Show, LocalName)]
+#[node(Locatable, Synthesize, Show, LocalName)]
 pub struct FigureNode {
     /// The content of the figure. Often, an [image]($func/image).
     #[required]
@@ -57,26 +57,24 @@ impl FigureNode {
 }
 
 impl Synthesize for FigureNode {
-    fn synthesize(&self, vt: &mut Vt, styles: StyleChain) -> Content {
-        let my_id = vt.identify(self);
+    fn synthesize(&mut self, vt: &Vt, styles: StyleChain) {
+        let my_id = self.0.stable_id().unwrap();
         let element = self.element();
 
-        let numbering = self.numbering(styles);
         let mut number = None;
+        let numbering = self.numbering(styles);
         if numbering.is_some() {
             number = NonZeroUsize::new(
                 1 + vt
-                    .locate(Selector::node::<Self>())
-                    .into_iter()
+                    .locate_node::<Self>()
                     .take_while(|&(id, _)| id != my_id)
-                    .filter(|(_, node)| node.to::<Self>().unwrap().element() == element)
+                    .filter(|(_, figure)| figure.element() == element)
                     .count(),
             );
         }
 
-        let node = self.clone().with_number(number).with_numbering(numbering).pack();
-        let meta = Meta::Node(my_id, node.clone());
-        node.styled(MetaNode::set_data(vec![meta]))
+        self.push_number(number);
+        self.push_numbering(numbering);
     }
 }
 

library/src/meta/heading.rs

@@ -40,7 +40,7 @@ use crate::text::{TextNode, TextSize};
 ///
 /// Display: Heading
 /// Category: meta
-#[node(Synthesize, Show, Finalize, LocalName)]
+#[node(Locatable, Synthesize, Show, Finalize, LocalName)]
 pub struct HeadingNode {
     /// The logical nesting depth of the heading, starting from one.
     #[default(NonZeroUsize::new(1).unwrap())]
@@ -83,19 +83,16 @@ pub struct HeadingNode {
 }
 
 impl Synthesize for HeadingNode {
-    fn synthesize(&self, vt: &mut Vt, styles: StyleChain) -> Content {
-        let my_id = vt.identify(self);
+    fn synthesize(&mut self, vt: &Vt, styles: StyleChain) {
+        let my_id = self.0.stable_id().unwrap();
         let numbering = self.numbering(styles);
 
         let mut counter = HeadingCounter::new();
         if numbering.is_some() {
             // Advance past existing headings.
-            for (_, node) in vt
-                .locate(Selector::node::<Self>())
-                .into_iter()
-                .take_while(|&(id, _)| id != my_id)
+            for (_, heading) in
+                vt.locate_node::<Self>().take_while(|&(id, _)| id != my_id)
             {
-                let heading = node.to::<Self>().unwrap();
                 if heading.numbering(StyleChain::default()).is_some() {
                     counter.advance(heading);
                 }
@@ -105,16 +102,10 @@ impl Synthesize for HeadingNode {
             counter.advance(self);
         }
 
-        let node = self
-            .clone()
-            .with_level(self.level(styles))
-            .with_outlined(self.outlined(styles))
-            .with_numbers(numbering.is_some().then(|| counter.take()))
-            .with_numbering(numbering)
-            .pack();
-
-        let meta = Meta::Node(my_id, node.clone());
-        node.styled(MetaNode::set_data(vec![meta]))
+        self.push_level(self.level(styles));
+        self.push_outlined(self.outlined(styles));
+        self.push_numbers(numbering.is_some().then(|| counter.take()));
+        self.push_numbering(numbering);
     }
 }
 

library/src/meta/link.rs

@@ -86,7 +86,7 @@ impl Show for LinkNode {
 impl Finalize for LinkNode {
     fn finalize(&self, realized: Content, _: StyleChain) -> Content {
         realized
-            .styled(MetaNode::set_data(vec![Meta::Link(self.dest())]))
+            .linked(self.dest())
             .styled(TextNode::set_hyphenate(Hyphenate(Smart::Custom(false))))
     }
 }

library/src/meta/outline.rs

@@ -74,15 +74,14 @@ pub struct OutlineNode {
 }
 
 impl Synthesize for OutlineNode {
-    fn synthesize(&self, vt: &mut Vt, _: StyleChain) -> Content {
+    fn synthesize(&mut self, vt: &Vt, _: StyleChain) {
         let headings = vt
-            .locate(Selector::node::<HeadingNode>())
-            .into_iter()
-            .map(|(_, node)| node.to::<HeadingNode>().unwrap().clone())
+            .locate_node::<HeadingNode>()
+            .map(|(_, node)| node.clone())
             .filter(|node| node.outlined(StyleChain::default()))
             .collect();
 
-        self.clone().with_headings(headings).pack()
+        self.push_headings(headings);
     }
 }
 

library/src/meta/reference.rs

@@ -37,9 +37,9 @@ use crate::text::TextNode;
 /// Category: meta
 #[node(Synthesize, Show)]
 pub struct RefNode {
-    /// The label that should be referenced.
+    /// The target label that should be referenced.
     #[required]
-    pub label: Label,
+    pub target: Label,
 
     /// The prefix before the referenced number.
     ///
@@ -59,20 +59,19 @@ pub struct RefNode {
     /// ```
     pub prefix: Smart<Option<Func>>,
 
-    /// All elements with the `target` label in the document.
+    /// All elements with the target label in the document.
     #[synthesized]
     pub matches: Vec<Content>,
 }
 
 impl Synthesize for RefNode {
-    fn synthesize(&self, vt: &mut Vt, _: StyleChain) -> Content {
+    fn synthesize(&mut self, vt: &Vt, _: StyleChain) {
         let matches = vt
-            .locate(Selector::Label(self.label()))
-            .into_iter()
+            .locate(Selector::Label(self.target()))
             .map(|(_, node)| node.clone())
             .collect();
 
-        self.clone().with_matches(matches).pack()
+        self.push_matches(matches);
     }
 }
 

library/src/prelude.rs

@@ -22,9 +22,9 @@ pub use typst::eval::{
 pub use typst::geom::*;
 #[doc(no_inline)]
 pub use typst::model::{
-    node, Construct, Content, Finalize, Fold, Introspector, Label, Node, NodeId, Resolve,
-    Selector, Set, Show, StabilityProvider, StyleChain, StyleMap, StyleVec, Synthesize,
-    Unlabellable, Vt,
+    node, Construct, Content, Finalize, Fold, Introspector, Label, Locatable, Node,
+    NodeId, Resolve, Selector, Set, Show, StabilityProvider, StableId, StyleChain,
+    StyleMap, StyleVec, Synthesize, Unlabellable, Vt,
 };
 #[doc(no_inline)]
 pub use typst::syntax::{Span, Spanned};

library/src/shared/ext.rs

@@ -42,7 +42,7 @@ impl ContentExt for Content {
     }
 
     fn linked(self, dest: Destination) -> Self {
-        self.styled(MetaNode::set_data(vec![Meta::Link(dest.clone())]))
+        self.styled(MetaNode::set_data(vec![Meta::Link(dest)]))
     }
 
     fn aligned(self, aligns: Axes<Option<GenAlign>>) -> Self {

library/src/text/raw.rs

@@ -121,8 +121,8 @@ impl RawNode {
 }
 
 impl Synthesize for RawNode {
-    fn synthesize(&self, _: &mut Vt, styles: StyleChain) -> Content {
-        self.clone().with_lang(self.lang(styles)).pack()
+    fn synthesize(&mut self, _: &Vt, styles: StyleChain) {
+        self.push_lang(self.lang(styles));
     }
 }
 

macros/src/node.rs

@@ -34,6 +34,7 @@ struct Field {
     ident: Ident,
     ident_in: Ident,
     with_ident: Ident,
+    push_ident: Ident,
     set_ident: Ident,
     ty: syn::Type,
     output: syn::Type,
@@ -81,6 +82,10 @@ fn prepare(stream: TokenStream, body: &syn::ItemStruct) -> Result<Node> {
         let required = has_attr(&mut attrs, "required") || variadic;
         let positional = has_attr(&mut attrs, "positional") || required;
 
+        if ident == "label" {
+            bail!(ident, "invalid field name");
+        }
+
         let mut field = Field {
             name: kebab_case(&ident),
             docs: documentation(&attrs),
@@ -100,6 +105,7 @@ fn prepare(stream: TokenStream, body: &syn::ItemStruct) -> Result<Node> {
             ident: ident.clone(),
             ident_in: Ident::new(&format!("{}_in", ident), ident.span()),
             with_ident: Ident::new(&format!("with_{}", ident), ident.span()),
+            push_ident: Ident::new(&format!("push_{}", ident), ident.span()),
             set_ident: Ident::new(&format!("set_{}", ident), ident.span()),
             ty: field.ty.clone(),
             output: field.ty.clone(),
@@ -162,17 +168,23 @@ fn create(node: &Node) -> TokenStream {
     let new = create_new_func(node);
     let field_methods = all.clone().map(create_field_method);
     let field_in_methods = settable.clone().map(create_field_in_method);
-    let with_fields_methods = all.map(create_with_field_method);
+    let with_field_methods = all.clone().map(create_with_field_method);
+    let push_field_methods = all.map(create_push_field_method);
     let field_style_methods = settable.map(create_set_field_method);
 
     // Trait implementations.
-    let construct = node
+    let node_impl = create_node_impl(node);
+    let construct_impl = node
         .capable
         .iter()
         .all(|capability| capability != "Construct")
         .then(|| create_construct_impl(node));
-    let set = create_set_impl(node);
-    let node = create_node_impl(node);
+    let set_impl = create_set_impl(node);
+    let locatable_impl = node
+        .capable
+        .iter()
+        .any(|capability| capability == "Locatable")
+        .then(|| quote! { impl ::typst::model::Locatable for #ident {} });
 
     quote! {
         #[doc = #docs]
@@ -184,7 +196,8 @@ fn create(node: &Node) -> TokenStream {
             #new
             #(#field_methods)*
             #(#field_in_methods)*
-            #(#with_fields_methods)*
+            #(#with_field_methods)*
+            #(#push_field_methods)*
             #(#field_style_methods)*
 
             /// The node's span.
@@ -193,9 +206,10 @@ fn create(node: &Node) -> TokenStream {
             }
         }
 
-        #node
-        #construct
-        #set
+        #node_impl
+        #construct_impl
+        #set_impl
+        #locatable_impl
 
         impl From<#ident> for ::typst::eval::Value {
             fn from(value: #ident) -> Self {
@@ -232,6 +246,7 @@ fn create_field_method(field: &Field) -> TokenStream {
     if field.inherent() || field.synthesized {
         quote! {
             #[doc = #docs]
+            #[track_caller]
             #vis fn #ident(&self) -> #output {
                 self.0.expect_field(#name)
             }
@@ -293,6 +308,18 @@ fn create_with_field_method(field: &Field) -> TokenStream {
     }
 }
 
+/// Create a set-style method for a field.
+fn create_push_field_method(field: &Field) -> TokenStream {
+    let Field { vis, ident, push_ident, name, ty, .. } = field;
+    let doc = format!("Push the [`{}`](Self::{}) field.", name, ident);
+    quote! {
+        #[doc = #doc]
+        #vis fn #push_ident(&mut self, #ident: #ty) {
+            self.0.push_field(#name, #ident);
+        }
+    }
+}
+
 /// Create a setter method for a field.
 fn create_set_field_method(field: &Field) -> TokenStream {
     let Field { vis, ident, set_ident, name, ty, .. } = field;

src/model/content.rs

@@ -8,7 +8,7 @@ use comemo::Tracked;
 use ecow::{eco_format, EcoString, EcoVec};
 use once_cell::sync::Lazy;
 
-use super::{node, Guard, Recipe, Style, StyleMap};
+use super::{node, Guard, Locatable, Recipe, StableId, Style, StyleMap, Synthesize};
 use crate::diag::{SourceResult, StrResult};
 use crate::eval::{
     cast_from_value, cast_to_value, Args, Cast, Func, FuncInfo, Str, Value, Vm,
@@ -29,8 +29,9 @@ pub struct Content {
 /// Modifiers that can be attached to content.
 #[derive(Debug, Clone, PartialEq, Hash)]
 enum Modifier {
-    Synthesized,
+    Prepared,
     Guard(Guard),
+    Id(StableId),
 }
 
 impl Content {
@@ -101,6 +102,16 @@ impl Content {
         Some(unsafe { &*crate::util::fat::from_raw_parts(data, vtable) })
     }
 
+    /// Cast to a trait object if this content has the given capability.
+    pub fn with_mut<C>(&mut self) -> Option<&mut C>
+    where
+        C: ?Sized + 'static,
+    {
+        let vtable = (self.id.0.vtable)(TypeId::of::<C>())?;
+        let data = self as *mut Self as *mut ();
+        Some(unsafe { &mut *crate::util::fat::from_raw_parts_mut(data, vtable) })
+    }
+
     /// The node's span.
     pub fn span(&self) -> Span {
         self.span
@@ -233,17 +244,6 @@ impl Content {
         self
     }
 
-    /// Mark this content as prepared.
-    pub fn synthesized(mut self) -> Self {
-        self.modifiers.push(Modifier::Synthesized);
-        self
-    }
-
-    /// Whether this node was prepared.
-    pub fn is_synthesized(&self) -> bool {
-        self.modifiers.contains(&Modifier::Synthesized)
-    }
-
     /// Whether no show rule was executed for this node so far.
     pub(super) fn is_pristine(&self) -> bool {
         !self
@@ -257,6 +257,37 @@ impl Content {
         self.modifiers.contains(&Modifier::Guard(id))
     }
 
+    /// Whether this node was prepared.
+    pub fn is_prepared(&self) -> bool {
+        self.modifiers.contains(&Modifier::Prepared)
+    }
+
+    /// Whether the node needs to be realized specially.
+    pub fn needs_preparation(&self) -> bool {
+        (self.can::<dyn Locatable>()
+            || self.can::<dyn Synthesize>()
+            || self.label().is_some())
+            && !self.is_prepared()
+    }
+
+    /// Mark this content as prepared.
+    pub fn mark_prepared(&mut self) {
+        self.modifiers.push(Modifier::Prepared);
+    }
+
+    /// Attach a stable id to this content.
+    pub fn set_stable_id(&mut self, id: StableId) {
+        self.modifiers.push(Modifier::Id(id));
+    }
+
+    /// This content's stable identifier.
+    pub fn stable_id(&self) -> Option<StableId> {
+        self.modifiers.iter().find_map(|modifier| match modifier {
+            Modifier::Id(id) => Some(*id),
+            _ => None,
+        })
+    }
+
     /// Copy the modifiers from another piece of content.
     pub(super) fn copy_modifiers(&mut self, from: &Content) {
         self.span = from.span;

src/model/realize.rs

@@ -1,9 +1,10 @@
 use super::{Content, NodeId, Recipe, Selector, StyleChain, Vt};
 use crate::diag::SourceResult;
+use crate::doc::{Meta, MetaNode};
 
 /// Whether the target is affected by show rules in the given style chain.
 pub fn applicable(target: &Content, styles: StyleChain) -> bool {
-    if target.can::<dyn Synthesize>() && !target.is_synthesized() {
+    if target.needs_preparation() {
         return true;
     }
 
@@ -31,21 +32,31 @@ pub fn realize(
     target: &Content,
     styles: StyleChain,
 ) -> SourceResult<Option<Content>> {
+    // Pre-process.
+    if target.needs_preparation() {
+        let mut node = target.clone();
+        if target.can::<dyn Locatable>() || target.label().is_some() {
+            let id = vt.identify(target);
+            node.set_stable_id(id);
+        }
+
+        if let Some(node) = node.with_mut::<dyn Synthesize>() {
+            node.synthesize(vt, styles);
+        }
+
+        node.mark_prepared();
+
+        if let Some(id) = node.stable_id() {
+            let meta = Meta::Node(id, node.clone());
+            return Ok(Some(node.styled(MetaNode::set_data(vec![meta]))));
+        }
+
+        return Ok(Some(node));
+    }
+
     // Find out how many recipes there are.
     let mut n = styles.recipes().count();
 
-    // Synthesize if not already happened for this node.
-    if target.can::<dyn Synthesize>() && !target.is_synthesized() {
-        return Ok(Some(
-            target
-                .clone()
-                .synthesized()
-                .with::<dyn Synthesize>()
-                .unwrap()
-                .synthesize(vt, styles),
-        ));
-    }
-
     // Find an applicable recipe.
     let mut realized = None;
     for recipe in styles.recipes() {
@@ -144,10 +155,13 @@ fn try_apply(
     }
 }
 
+/// Makes this node locatable through `vt.locate`.
+pub trait Locatable {}
+
 /// Synthesize fields on a node. This happens before execution of any show rule.
 pub trait Synthesize {
     /// Prepare the node for show rule application.
-    fn synthesize(&self, vt: &mut Vt, styles: StyleChain) -> Content;
+    fn synthesize(&mut self, vt: &Vt, styles: StyleChain);
 }
 
 /// The base recipe for a node.

src/model/typeset.rs

@@ -5,7 +5,7 @@ use std::num::NonZeroUsize;
 
 use comemo::{Track, Tracked, TrackedMut};
 
-use super::{Content, Selector, StyleChain};
+use super::{Content, Node, Selector, StyleChain};
 use crate::diag::SourceResult;
 use crate::doc::{Document, Element, Frame, Location, Meta};
 use crate::geom::Transform;
@@ -83,8 +83,17 @@ impl<'a> Vt<'a> {
     }
 
     /// Locate all metadata matches for the given selector.
-    pub fn locate(&self, selector: Selector) -> Vec<(StableId, &Content)> {
-        self.introspector.locate(selector)
+    pub fn locate(
+        &self,
+        selector: Selector,
+    ) -> impl Iterator<Item = (StableId, &Content)> {
+        self.introspector.locate(selector).into_iter()
+    }
+
+    /// Locate all metadata matches for the given node.
+    pub fn locate_node<T: Node>(&self) -> impl Iterator<Item = (StableId, &T)> {
+        self.locate(Selector::node::<T>())
+            .map(|(id, content)| (id, content.to::<T>().unwrap()))
     }
 }
 

tests/typ/compiler/set.typ

@@ -51,8 +51,8 @@ Hello *#x*
 ---
 // Test conditional set.
 #show ref: it => {
-  set text(red) if it.label == <unknown>
-  "@" + str(it.label)
+  set text(red) if it.target == <unknown>
+  "@" + str(it.target)
 }
 
 @hello from the @unknown