2025-02-03 16:04:54 +00:00

1447 lines
44 KiB
Rust

//! Text handling.
mod case;
mod deco;
mod font;
mod item;
mod lang;
mod linebreak;
#[path = "lorem.rs"]
mod lorem_;
mod raw;
mod shift;
#[path = "smallcaps.rs"]
mod smallcaps_;
mod smartquote;
mod space;
pub use self::case::*;
pub use self::deco::*;
pub use self::font::*;
pub use self::item::*;
pub use self::lang::*;
pub use self::linebreak::*;
pub use self::lorem_::*;
pub use self::raw::*;
pub use self::shift::*;
pub use self::smallcaps_::*;
pub use self::smartquote::*;
pub use self::space::*;
use std::fmt::{self, Debug, Formatter};
use std::hash::Hash;
use std::sync::LazyLock;
use ecow::{eco_format, EcoString};
use icu_properties::sets::CodePointSetData;
use icu_provider::AsDeserializingBufferProvider;
use icu_provider_blob::BlobDataProvider;
use rustybuzz::Feature;
use smallvec::SmallVec;
use ttf_parser::Tag;
use typst_syntax::Spanned;
use typst_utils::singleton;
use crate::diag::{bail, warning, HintedStrResult, SourceResult};
use crate::engine::Engine;
use crate::foundations::{
cast, category, dict, elem, Args, Array, Cast, Category, Construct, Content, Dict,
Fold, IntoValue, NativeElement, Never, NoneValue, Packed, PlainText, Regex, Repr,
Resolve, Scope, Set, Smart, StyleChain,
};
use crate::layout::{Abs, Axis, Dir, Em, Length, Ratio, Rel};
use crate::math::{EquationElem, MathSize};
use crate::model::ParElem;
use crate::visualize::{Color, Paint, RelativeTo, Stroke};
use crate::World;
/// Text styling.
///
/// The [text function]($text) is of particular interest.
#[category]
pub static TEXT: Category;
/// Hook up all `text` definitions.
pub(super) fn define(global: &mut Scope) {
global.start_category(TEXT);
global.define_elem::<TextElem>();
global.define_elem::<LinebreakElem>();
global.define_elem::<SmartQuoteElem>();
global.define_elem::<SubElem>();
global.define_elem::<SuperElem>();
global.define_elem::<UnderlineElem>();
global.define_elem::<OverlineElem>();
global.define_elem::<StrikeElem>();
global.define_elem::<HighlightElem>();
global.define_elem::<SmallcapsElem>();
global.define_elem::<RawElem>();
global.define_func::<lower>();
global.define_func::<upper>();
global.define_func::<lorem>();
}
/// Customizes the look and layout of text in a variety of ways.
///
/// This function is used frequently, both with set rules and directly. While
/// the set rule is often the simpler choice, calling the `text` function
/// directly can be useful when passing text as an argument to another function.
///
/// # Example
/// ```example
/// #set text(18pt)
/// With a set rule.
///
/// #emph(text(blue)[
/// With a function call.
/// ])
/// ```
#[elem(Debug, Construct, PlainText, Repr)]
pub struct TextElem {
/// A font family descriptor or priority list of font family descriptor.
///
/// A font family descriptor can be a plain string representing the family
/// name or a dictionary with the following keys:
///
/// - `name` (required): The font family name.
/// - `covers` (optional): Defines the Unicode codepoints for which the
/// family shall be used. This can be:
/// - A predefined coverage set:
/// - `{"latin-in-cjk"}` covers all codepoints except for those which
/// exist in Latin fonts, but should preferrably be taken from CJK
/// fonts.
/// - A [regular expression]($regex) that defines exactly which codepoints
/// shall be covered. Accepts only the subset of regular expressions
/// which consist of exactly one dot, letter, or character class.
///
/// When processing text, Typst tries all specified font families in order
/// until it finds a font that has the necessary glyphs. In the example
/// below, the font `Inria Serif` is preferred, but since it does not
/// contain Arabic glyphs, the arabic text uses `Noto Sans Arabic` instead.
///
/// The collection of available fonts differs by platform:
///
/// - In the web app, you can see the list of available fonts by clicking on
/// the "Ag" button. You can provide additional fonts by uploading `.ttf`
/// or `.otf` files into your project. They will be discovered
/// automatically. The priority is: project fonts > server fonts.
///
/// - Locally, Typst uses your installed system fonts or embedded fonts in
/// the CLI, which are `Libertinus Serif`, `New Computer Modern`,
/// `New Computer Modern Math`, and `DejaVu Sans Mono`. In addition, you
/// can use the `--font-path` argument or `TYPST_FONT_PATHS` environment
/// variable to add directories that should be scanned for fonts. The
/// priority is: `--font-paths` > system fonts > embedded fonts. Run
/// `typst fonts` to see the fonts that Typst has discovered on your
/// system. Note that you can pass the `--ignore-system-fonts` parameter
/// to the CLI to ensure Typst won't search for system fonts.
///
/// ```example
/// #set text(font: "PT Sans")
/// This is sans-serif.
///
/// #set text(font: (
/// "Inria Serif",
/// "Noto Sans Arabic",
/// ))
///
/// This is Latin. \
/// هذا عربي.
///
/// // Change font only for numbers.
/// #set text(font: (
/// (name: "PT Sans", covers: regex("[0-9]")),
/// "Libertinus Serif"
/// ))
///
/// The number 123.
///
/// // Mix Latin and CJK fonts.
/// #set text(font: (
/// (name: "Inria Serif", covers: "latin-in-cjk"),
/// "Noto Serif CJK SC"
/// ))
/// 分别设置“中文”和English字体
/// ```
#[parse({
let font_list: Option<Spanned<FontList>> = args.named("font")?;
if let Some(list) = &font_list {
check_font_list(engine, list);
}
font_list.map(|font_list| font_list.v)
})]
#[default(FontList(vec![FontFamily::new("Libertinus Serif")]))]
#[borrowed]
#[ghost]
pub font: FontList,
/// Whether to allow last resort font fallback when the primary font list
/// contains no match. This lets Typst search through all available fonts
/// for the most similar one that has the necessary glyphs.
///
/// _Note:_ Currently, there are no warnings when fallback is disabled and
/// no glyphs are found. Instead, your text shows up in the form of "tofus":
/// Small boxes that indicate the lack of an appropriate glyph. In the
/// future, you will be able to instruct Typst to issue warnings so you know
/// something is up.
///
/// ```example
/// #set text(font: "Inria Serif")
/// هذا عربي
///
/// #set text(fallback: false)
/// هذا عربي
/// ```
#[default(true)]
#[ghost]
pub fallback: bool,
/// The desired font style.
///
/// When an italic style is requested and only an oblique one is available,
/// it is used. Similarly, the other way around, an italic style can stand
/// in for an oblique one. When neither an italic nor an oblique style is
/// available, Typst selects the normal style. Since most fonts are only
/// available either in an italic or oblique style, the difference between
/// italic and oblique style is rarely observable.
///
/// If you want to emphasize your text, you should do so using the [emph]
/// function instead. This makes it easy to adapt the style later if you
/// change your mind about how to signify the emphasis.
///
/// ```example
/// #text(font: "Libertinus Serif", style: "italic")[Italic]
/// #text(font: "DejaVu Sans", style: "oblique")[Oblique]
/// ```
#[ghost]
pub style: FontStyle,
/// The desired thickness of the font's glyphs. Accepts an integer between
/// `{100}` and `{900}` or one of the predefined weight names. When the
/// desired weight is not available, Typst selects the font from the family
/// that is closest in weight.
///
/// If you want to strongly emphasize your text, you should do so using the
/// [strong] function instead. This makes it easy to adapt the style later
/// if you change your mind about how to signify the strong emphasis.
///
/// ```example
/// #set text(font: "IBM Plex Sans")
///
/// #text(weight: "light")[Light] \
/// #text(weight: "regular")[Regular] \
/// #text(weight: "medium")[Medium] \
/// #text(weight: 500)[Medium] \
/// #text(weight: "bold")[Bold]
/// ```
#[ghost]
pub weight: FontWeight,
/// The desired width of the glyphs. Accepts a ratio between `{50%}` and
/// `{200%}`. When the desired width is not available, Typst selects the
/// font from the family that is closest in stretch. This will only stretch
/// the text if a condensed or expanded version of the font is available.
///
/// If you want to adjust the amount of space between characters instead of
/// stretching the glyphs itself, use the [`tracking`]($text.tracking)
/// property instead.
///
/// ```example
/// #text(stretch: 75%)[Condensed] \
/// #text(stretch: 100%)[Normal]
/// ```
#[ghost]
pub stretch: FontStretch,
/// The size of the glyphs. This value forms the basis of the `em` unit:
/// `{1em}` is equivalent to the font size.
///
/// You can also give the font size itself in `em` units. Then, it is
/// relative to the previous font size.
///
/// ```example
/// #set text(size: 20pt)
/// very #text(1.5em)[big] text
/// ```
#[parse(args.named_or_find("size")?)]
#[fold]
#[default(TextSize(Abs::pt(11.0).into()))]
#[resolve]
#[ghost]
pub size: TextSize,
/// The glyph fill paint.
///
/// ```example
/// #set text(fill: red)
/// This text is red.
/// ```
#[parse({
let paint: Option<Spanned<Paint>> = args.named_or_find("fill")?;
if let Some(paint) = &paint {
if paint.v.relative() == Smart::Custom(RelativeTo::Self_) {
bail!(
paint.span,
"gradients and tilings on text must be relative to the parent";
hint: "make sure to set `relative: auto` on your text fill"
);
}
}
paint.map(|paint| paint.v)
})]
#[default(Color::BLACK.into())]
#[ghost]
pub fill: Paint,
/// How to stroke the text.
///
/// ```example
/// #text(stroke: 0.5pt + red)[Stroked]
/// ```
#[resolve]
#[ghost]
pub stroke: Option<Stroke>,
/// The amount of space that should be added between characters.
///
/// ```example
/// #set text(tracking: 1.5pt)
/// Distant text.
/// ```
#[resolve]
#[ghost]
pub tracking: Length,
/// The amount of space between words.
///
/// Can be given as an absolute length, but also relative to the width of
/// the space character in the font.
///
/// If you want to adjust the amount of space between characters rather than
/// words, use the [`tracking`]($text.tracking) property instead.
///
/// ```example
/// #set text(spacing: 200%)
/// Text with distant words.
/// ```
#[resolve]
#[default(Rel::one())]
#[ghost]
pub spacing: Rel<Length>,
/// Whether to automatically insert spacing between CJK and Latin characters.
///
/// ```example
/// #set text(cjk-latin-spacing: auto)
/// 第4章介绍了基本的API。
///
/// #set text(cjk-latin-spacing: none)
/// 第4章介绍了基本的API。
/// ```
#[ghost]
pub cjk_latin_spacing: Smart<Option<Never>>,
/// An amount to shift the text baseline by.
///
/// ```example
/// A #text(baseline: 3pt)[lowered]
/// word.
/// ```
#[resolve]
#[ghost]
pub baseline: Length,
/// Whether certain glyphs can hang over into the margin in justified text.
/// This can make justification visually more pleasing.
///
/// ```example
/// #set par(justify: true)
/// This justified text has a hyphen in
/// the paragraph's first line. Hanging
/// the hyphen slightly into the margin
/// results in a clearer paragraph edge.
///
/// #set text(overhang: false)
/// This justified text has a hyphen in
/// the paragraph's first line. Hanging
/// the hyphen slightly into the margin
/// results in a clearer paragraph edge.
/// ```
#[default(true)]
#[ghost]
pub overhang: bool,
/// The top end of the conceptual frame around the text used for layout and
/// positioning. This affects the size of containers that hold text.
///
/// ```example
/// #set rect(inset: 0pt)
/// #set text(size: 20pt)
///
/// #set text(top-edge: "ascender")
/// #rect(fill: aqua)[Typst]
///
/// #set text(top-edge: "cap-height")
/// #rect(fill: aqua)[Typst]
/// ```
#[default(TopEdge::Metric(TopEdgeMetric::CapHeight))]
#[ghost]
pub top_edge: TopEdge,
/// The bottom end of the conceptual frame around the text used for layout
/// and positioning. This affects the size of containers that hold text.
///
/// ```example
/// #set rect(inset: 0pt)
/// #set text(size: 20pt)
///
/// #set text(bottom-edge: "baseline")
/// #rect(fill: aqua)[Typst]
///
/// #set text(bottom-edge: "descender")
/// #rect(fill: aqua)[Typst]
/// ```
#[default(BottomEdge::Metric(BottomEdgeMetric::Baseline))]
#[ghost]
pub bottom_edge: BottomEdge,
/// An [ISO 639-1/2/3 language code.](https://en.wikipedia.org/wiki/ISO_639)
///
/// Setting the correct language affects various parts of Typst:
///
/// - The text processing pipeline can make more informed choices.
/// - Hyphenation will use the correct patterns for the language.
/// - [Smart quotes]($smartquote) turns into the correct quotes for the
/// language.
/// - And all other things which are language-aware.
///
/// ```example
/// #set text(lang: "de")
/// #outline()
///
/// = Einleitung
/// In diesem Dokument, ...
/// ```
#[default(Lang::ENGLISH)]
#[ghost]
pub lang: Lang,
/// An [ISO 3166-1 alpha-2 region code.](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2)
///
/// This lets the text processing pipeline make more informed choices.
#[ghost]
pub region: Option<Region>,
/// The OpenType writing script.
///
/// The combination of `{lang}` and `{script}` determine how font features,
/// such as glyph substitution, are implemented. Frequently the value is a
/// modified (all-lowercase) ISO 15924 script identifier, and the `math`
/// writing script is used for features appropriate for mathematical
/// symbols.
///
/// When set to `{auto}`, the default and recommended setting, an
/// appropriate script is chosen for each block of characters sharing a
/// common Unicode script property.
///
/// ```example
/// #set text(
/// font: "Libertinus Serif",
/// size: 20pt,
/// )
///
/// #let scedilla = [Ş]
/// #scedilla // S with a cedilla
///
/// #set text(lang: "ro", script: "latn")
/// #scedilla // S with a subscript comma
///
/// #set text(lang: "ro", script: "grek")
/// #scedilla // S with a cedilla
/// ```
#[ghost]
pub script: Smart<WritingScript>,
/// The dominant direction for text and inline objects. Possible values are:
///
/// - `{auto}`: Automatically infer the direction from the `lang` property.
/// - `{ltr}`: Layout text from left to right.
/// - `{rtl}`: Layout text from right to left.
///
/// When writing in right-to-left scripts like Arabic or Hebrew, you should
/// set the [text language]($text.lang) or direction. While individual runs
/// of text are automatically layouted in the correct direction, setting the
/// dominant direction gives the bidirectional reordering algorithm the
/// necessary information to correctly place punctuation and inline objects.
/// Furthermore, setting the direction affects the alignment values `start`
/// and `end`, which are equivalent to `left` and `right` in `ltr` text and
/// the other way around in `rtl` text.
///
/// If you set this to `rtl` and experience bugs or in some way bad looking
/// output, please get in touch with us through the
/// [Forum](https://forum.typst.app/),
/// [Discord server](https://discord.gg/2uDybryKPe),
/// or our [contact form](https://typst.app/contact).
///
/// ```example
/// #set text(dir: rtl)
/// هذا عربي.
/// ```
#[resolve]
#[ghost]
pub dir: TextDir,
/// Whether to hyphenate text to improve line breaking. When `{auto}`, text
/// will be hyphenated if and only if justification is enabled.
///
/// Setting the [text language]($text.lang) ensures that the correct
/// hyphenation patterns are used.
///
/// ```example
/// #set page(width: 200pt)
///
/// #set par(justify: true)
/// This text illustrates how
/// enabling hyphenation can
/// improve justification.
///
/// #set text(hyphenate: false)
/// This text illustrates how
/// enabling hyphenation can
/// improve justification.
/// ```
#[resolve]
#[ghost]
pub hyphenate: Hyphenate,
/// The "cost" of various choices when laying out text. A higher cost means
/// the layout engine will make the choice less often. Costs are specified
/// as a ratio of the default cost, so `{50%}` will make text layout twice
/// as eager to make a given choice, while `{200%}` will make it half as
/// eager.
///
/// Currently, the following costs can be customized:
/// - `hyphenation`: splitting a word across multiple lines
/// - `runt`: ending a paragraph with a line with a single word
/// - `widow`: leaving a single line of paragraph on the next page
/// - `orphan`: leaving single line of paragraph on the previous page
///
/// Hyphenation is generally avoided by placing the whole word on the next
/// line, so a higher hyphenation cost can result in awkward justification
/// spacing. Note: Hyphenation costs will only be applied when the
/// [`linebreaks`]($par.linebreaks) are set to "optimized". (For example
/// by default implied by [`justify`]($par.justify).)
///
/// Runts are avoided by placing more or fewer words on previous lines, so a
/// higher runt cost can result in more awkward in justification spacing.
///
/// Text layout prevents widows and orphans by default because they are
/// generally discouraged by style guides. However, in some contexts they
/// are allowed because the prevention method, which moves a line to the
/// next page, can result in an uneven number of lines between pages. The
/// `widow` and `orphan` costs allow disabling these modifications.
/// (Currently, `{0%}` allows widows/orphans; anything else, including the
/// default of `{100%}`, prevents them. More nuanced cost specification for
/// these modifications is planned for the future.)
///
/// ```example
/// #set text(hyphenate: true, size: 11.4pt)
/// #set par(justify: true)
///
/// #lorem(10)
///
/// // Set hyphenation to ten times the normal cost.
/// #set text(costs: (hyphenation: 1000%))
///
/// #lorem(10)
/// ```
#[fold]
#[ghost]
pub costs: Costs,
/// Whether to apply kerning.
///
/// When enabled, specific letter pairings move closer together or further
/// apart for a more visually pleasing result. The example below
/// demonstrates how decreasing the gap between the "T" and "o" results in a
/// more natural look. Setting this to `{false}` disables kerning by turning
/// off the OpenType `kern` font feature.
///
/// ```example
/// #set text(size: 25pt)
/// Totally
///
/// #set text(kerning: false)
/// Totally
/// ```
#[default(true)]
#[ghost]
pub kerning: bool,
/// Whether to apply stylistic alternates.
///
/// Sometimes fonts contain alternative glyphs for the same codepoint.
/// Setting this to `{true}` switches to these by enabling the OpenType
/// `salt` font feature.
///
/// ```example
/// #set text(
/// font: "IBM Plex Sans",
/// size: 20pt,
/// )
///
/// 0, a, g, ß
///
/// #set text(alternates: true)
/// 0, a, g, ß
/// ```
#[default(false)]
#[ghost]
pub alternates: bool,
/// Which stylistic sets to apply. Font designers can categorize alternative
/// glyphs forms into stylistic sets. As this value is highly font-specific,
/// you need to consult your font to know which sets are available.
///
/// This can be set to an integer or an array of integers, all
/// of which must be between `{1}` and `{20}`, enabling the
/// corresponding OpenType feature(s) from `ss01` to `ss20`.
/// Setting this to `{none}` will disable all stylistic sets.
///
/// ```example
/// #set text(font: "IBM Plex Serif")
/// ß vs #text(stylistic-set: 5)[ß] \
/// 10 years ago vs #text(stylistic-set: (1, 2, 3))[10 years ago]
/// ```
#[ghost]
pub stylistic_set: StylisticSets,
/// Whether standard ligatures are active.
///
/// Certain letter combinations like "fi" are often displayed as a single
/// merged glyph called a _ligature._ Setting this to `{false}` disables
/// these ligatures by turning off the OpenType `liga` and `clig` font
/// features.
///
/// ```example
/// #set text(size: 20pt)
/// A fine ligature.
///
/// #set text(ligatures: false)
/// A fine ligature.
/// ```
#[default(true)]
#[ghost]
pub ligatures: bool,
/// Whether ligatures that should be used sparingly are active. Setting this
/// to `{true}` enables the OpenType `dlig` font feature.
#[default(false)]
#[ghost]
pub discretionary_ligatures: bool,
/// Whether historical ligatures are active. Setting this to `{true}`
/// enables the OpenType `hlig` font feature.
#[default(false)]
#[ghost]
pub historical_ligatures: bool,
/// Which kind of numbers / figures to select. When set to `{auto}`, the
/// default numbers for the font are used.
///
/// ```example
/// #set text(font: "Noto Sans", 20pt)
/// #set text(number-type: "lining")
/// Number 9.
///
/// #set text(number-type: "old-style")
/// Number 9.
/// ```
#[ghost]
pub number_type: Smart<NumberType>,
/// The width of numbers / figures. When set to `{auto}`, the default
/// numbers for the font are used.
///
/// ```example
/// #set text(font: "Noto Sans", 20pt)
/// #set text(number-width: "proportional")
/// A 12 B 34. \
/// A 56 B 78.
///
/// #set text(number-width: "tabular")
/// A 12 B 34. \
/// A 56 B 78.
/// ```
#[ghost]
pub number_width: Smart<NumberWidth>,
/// Whether to have a slash through the zero glyph. Setting this to `{true}`
/// enables the OpenType `zero` font feature.
///
/// ```example
/// 0, #text(slashed-zero: true)[0]
/// ```
#[default(false)]
#[ghost]
pub slashed_zero: bool,
/// Whether to turn numbers into fractions. Setting this to `{true}`
/// enables the OpenType `frac` font feature.
///
/// It is not advisable to enable this property globally as it will mess
/// with all appearances of numbers after a slash (e.g., in URLs). Instead,
/// enable it locally when you want a fraction.
///
/// ```example
/// 1/2 \
/// #text(fractions: true)[1/2]
/// ```
#[default(false)]
#[ghost]
pub fractions: bool,
/// Raw OpenType features to apply.
///
/// - If given an array of strings, sets the features identified by the
/// strings to `{1}`.
/// - If given a dictionary mapping to numbers, sets the features
/// identified by the keys to the values.
///
/// ```example
/// // Enable the `frac` feature manually.
/// #set text(features: ("frac",))
/// 1/2
/// ```
#[fold]
#[ghost]
pub features: FontFeatures,
/// Content in which all text is styled according to the other arguments.
#[external]
#[required]
pub body: Content,
/// The text.
#[required]
pub text: EcoString,
/// The offset of the text in the text syntax node referenced by this
/// element's span.
#[internal]
#[ghost]
pub span_offset: usize,
/// A delta to apply on the font weight.
#[internal]
#[fold]
#[ghost]
pub delta: WeightDelta,
/// Whether the font style should be inverted.
#[internal]
#[fold]
#[default(ItalicToggle(false))]
#[ghost]
pub emph: ItalicToggle,
/// Decorative lines.
#[internal]
#[fold]
#[ghost]
pub deco: SmallVec<[Decoration; 1]>,
/// A case transformation that should be applied to the text.
#[internal]
#[ghost]
pub case: Option<Case>,
/// Whether small capital glyphs should be used. ("smcp", "c2sc")
#[internal]
#[ghost]
pub smallcaps: Option<Smallcaps>,
}
impl TextElem {
/// Create a new packed text element.
pub fn packed(text: impl Into<EcoString>) -> Content {
Self::new(text.into()).pack()
}
}
impl Debug for TextElem {
fn fmt(&self, f: &mut Formatter) -> fmt::Result {
write!(f, "Text({})", self.text)
}
}
impl Repr for TextElem {
fn repr(&self) -> EcoString {
eco_format!("[{}]", self.text)
}
}
impl Construct for TextElem {
fn construct(engine: &mut Engine, args: &mut Args) -> SourceResult<Content> {
// The text constructor is special: It doesn't create a text element.
// Instead, it leaves the passed argument structurally unchanged, but
// styles all text in it.
let styles = Self::set(engine, args)?;
let body = args.expect::<Content>("body")?;
Ok(body.styled_with_map(styles))
}
}
impl PlainText for Packed<TextElem> {
fn plain_text(&self, text: &mut EcoString) {
text.push_str(&self.text);
}
}
/// A lowercased font family like "arial".
#[derive(Debug, Clone, PartialEq, Hash)]
pub struct FontFamily {
// The name of the font family
name: EcoString,
// A regex that defines the Unicode codepoints supported by the font.
covers: Option<Covers>,
}
impl FontFamily {
/// Create a named font family variant.
pub fn new(string: &str) -> Self {
Self::with_coverage(string, None)
}
/// Create a font family by name and optional Unicode coverage.
pub fn with_coverage(string: &str, covers: Option<Covers>) -> Self {
Self { name: string.to_lowercase().into(), covers }
}
/// The lowercased family name.
pub fn as_str(&self) -> &str {
&self.name
}
/// The user-set coverage of the font family.
pub fn covers(&self) -> Option<&Regex> {
self.covers.as_ref().map(|covers| covers.as_regex())
}
}
cast! {
FontFamily,
self => self.name.into_value(),
string: EcoString => Self::new(&string),
mut v: Dict => {
let ret = Self::with_coverage(
&v.take("name")?.cast::<EcoString>()?,
v.take("covers").ok().map(|v| v.cast()).transpose()?
);
v.finish(&["name", "covers"])?;
ret
},
}
/// Defines which codepoints a font family will be used for.
#[derive(Debug, Clone, PartialEq, Hash)]
pub enum Covers {
/// Covers all codepoints except those used both in Latin and CJK fonts.
LatinInCjk,
/// Covers the set of codepoints for which the regex matches.
Regex(Regex),
}
impl Covers {
/// Retrieve the regex for the coverage.
pub fn as_regex(&self) -> &Regex {
match self {
Self::LatinInCjk => singleton!(
Regex,
Regex::new(
"[^\u{00B7}\u{2013}\u{2014}\u{2018}\u{2019}\
\u{201C}\u{201D}\u{2025}-\u{2027}\u{2E3A}]"
)
.unwrap()
),
Self::Regex(regex) => regex,
}
}
}
cast! {
Covers,
self => match self {
Self::LatinInCjk => "latin-in-cjk".into_value(),
Self::Regex(regex) => regex.into_value(),
},
/// Covers all codepoints except those used both in Latin and CJK fonts.
"latin-in-cjk" => Covers::LatinInCjk,
regex: Regex => {
let ast = regex_syntax::ast::parse::Parser::new().parse(regex.as_str());
match ast {
Ok(
regex_syntax::ast::Ast::ClassBracketed(..)
| regex_syntax::ast::Ast::ClassUnicode(..)
| regex_syntax::ast::Ast::ClassPerl(..)
| regex_syntax::ast::Ast::Dot(..)
| regex_syntax::ast::Ast::Literal(..),
) => {}
_ => bail!(
"coverage regex may only use dot, letters, and character classes";
hint: "the regex is applied to each letter individually"
),
}
Covers::Regex(regex)
},
}
/// Font family fallback list.
#[derive(Debug, Default, Clone, PartialEq, Hash)]
pub struct FontList(pub Vec<FontFamily>);
impl<'a> IntoIterator for &'a FontList {
type IntoIter = std::slice::Iter<'a, FontFamily>;
type Item = &'a FontFamily;
fn into_iter(self) -> Self::IntoIter {
self.0.iter()
}
}
cast! {
FontList,
self => if self.0.len() == 1 {
self.0.into_iter().next().unwrap().name.into_value()
} else {
self.0.into_value()
},
family: FontFamily => Self(vec![family]),
values: Array => Self(values.into_iter().map(|v| v.cast()).collect::<HintedStrResult<_>>()?),
}
/// Resolve a prioritized iterator over the font families.
pub fn families(styles: StyleChain) -> impl Iterator<Item = &FontFamily> + Clone {
let fallbacks = singleton!(Vec<FontFamily>, {
[
"libertinus serif",
"twitter color emoji",
"noto color emoji",
"apple color emoji",
"segoe ui emoji",
]
.into_iter()
.map(FontFamily::new)
.collect()
});
let tail = if TextElem::fallback_in(styles) { fallbacks.as_slice() } else { &[] };
TextElem::font_in(styles).into_iter().chain(tail.iter())
}
/// Resolve the font variant.
pub fn variant(styles: StyleChain) -> FontVariant {
let mut variant = FontVariant::new(
TextElem::style_in(styles),
TextElem::weight_in(styles),
TextElem::stretch_in(styles),
);
let WeightDelta(delta) = TextElem::delta_in(styles);
variant.weight = variant
.weight
.thicken(delta.clamp(i16::MIN as i64, i16::MAX as i64) as i16);
if TextElem::emph_in(styles).0 {
variant.style = match variant.style {
FontStyle::Normal => FontStyle::Italic,
FontStyle::Italic => FontStyle::Normal,
FontStyle::Oblique => FontStyle::Normal,
}
}
variant
}
/// The size of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub struct TextSize(pub Length);
impl Fold for TextSize {
fn fold(self, outer: Self) -> Self {
// Multiply the two linear functions.
Self(Length {
em: Em::new(self.0.em.get() * outer.0.em.get()),
abs: self.0.em.get() * outer.0.abs + self.0.abs,
})
}
}
impl Resolve for TextSize {
type Output = Abs;
fn resolve(self, styles: StyleChain) -> Self::Output {
let factor = match EquationElem::size_in(styles) {
MathSize::Display | MathSize::Text => 1.0,
MathSize::Script => EquationElem::script_scale_in(styles).0 as f64 / 100.0,
MathSize::ScriptScript => {
EquationElem::script_scale_in(styles).1 as f64 / 100.0
}
};
factor * self.0.resolve(styles)
}
}
cast! {
TextSize,
self => self.0.into_value(),
v: Length => Self(v),
}
/// Specifies the top edge of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub enum TopEdge {
/// An edge specified via font metrics or bounding box.
Metric(TopEdgeMetric),
/// An edge specified as a length.
Length(Length),
}
cast! {
TopEdge,
self => match self {
Self::Metric(metric) => metric.into_value(),
Self::Length(length) => length.into_value(),
},
v: TopEdgeMetric => Self::Metric(v),
v: Length => Self::Length(v),
}
/// Metrics that describe the top edge of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
pub enum TopEdgeMetric {
/// The font's ascender, which typically exceeds the height of all glyphs.
Ascender,
/// The approximate height of uppercase letters.
CapHeight,
/// The approximate height of non-ascending lowercase letters.
XHeight,
/// The baseline on which the letters rest.
Baseline,
/// The top edge of the glyph's bounding box.
Bounds,
}
impl TryInto<VerticalFontMetric> for TopEdgeMetric {
type Error = ();
fn try_into(self) -> Result<VerticalFontMetric, Self::Error> {
match self {
Self::Ascender => Ok(VerticalFontMetric::Ascender),
Self::CapHeight => Ok(VerticalFontMetric::CapHeight),
Self::XHeight => Ok(VerticalFontMetric::XHeight),
Self::Baseline => Ok(VerticalFontMetric::Baseline),
_ => Err(()),
}
}
}
/// Specifies the top edge of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub enum BottomEdge {
/// An edge specified via font metrics or bounding box.
Metric(BottomEdgeMetric),
/// An edge specified as a length.
Length(Length),
}
cast! {
BottomEdge,
self => match self {
Self::Metric(metric) => metric.into_value(),
Self::Length(length) => length.into_value(),
},
v: BottomEdgeMetric => Self::Metric(v),
v: Length => Self::Length(v),
}
/// Metrics that describe the bottom edge of text.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
pub enum BottomEdgeMetric {
/// The baseline on which the letters rest.
Baseline,
/// The font's descender, which typically exceeds the depth of all glyphs.
Descender,
/// The bottom edge of the glyph's bounding box.
Bounds,
}
impl TryInto<VerticalFontMetric> for BottomEdgeMetric {
type Error = ();
fn try_into(self) -> Result<VerticalFontMetric, Self::Error> {
match self {
Self::Baseline => Ok(VerticalFontMetric::Baseline),
Self::Descender => Ok(VerticalFontMetric::Descender),
_ => Err(()),
}
}
}
/// The direction of text and inline objects in their line.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)]
pub struct TextDir(pub Smart<Dir>);
cast! {
TextDir,
self => self.0.into_value(),
v: Smart<Dir> => {
if v.is_custom_and(|dir| dir.axis() == Axis::Y) {
bail!("text direction must be horizontal");
}
Self(v)
},
}
impl Resolve for TextDir {
type Output = Dir;
fn resolve(self, styles: StyleChain) -> Self::Output {
match self.0 {
Smart::Auto => TextElem::lang_in(styles).dir(),
Smart::Custom(dir) => dir,
}
}
}
/// Whether to hyphenate text.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)]
pub struct Hyphenate(pub Smart<bool>);
cast! {
Hyphenate,
self => self.0.into_value(),
v: Smart<bool> => Self(v),
}
impl Resolve for Hyphenate {
type Output = bool;
fn resolve(self, styles: StyleChain) -> Self::Output {
match self.0 {
Smart::Auto => ParElem::justify_in(styles),
Smart::Custom(v) => v,
}
}
}
/// A set of stylistic sets to enable.
#[derive(Debug, Copy, Clone, Default, Eq, PartialEq, Hash)]
pub struct StylisticSets(u32);
impl StylisticSets {
/// Converts this set into a Typst array of values.
pub fn into_array(self) -> Array {
self.sets().map(IntoValue::into_value).collect()
}
/// Returns whether this set contains a particular stylistic set.
pub fn has(self, ss: u8) -> bool {
self.0 & (1 << (ss as u32)) != 0
}
/// Returns an iterator over all stylistic sets to enable.
pub fn sets(self) -> impl Iterator<Item = u8> {
(1..=20).filter(move |i| self.has(*i))
}
}
cast! {
StylisticSets,
self => self.into_array().into_value(),
_: NoneValue => Self(0),
v: i64 => match v {
1 ..= 20 => Self(1 << (v as u32)),
_ => bail!("stylistic set must be between 1 and 20"),
},
v: Vec<i64> => {
let mut flags = 0;
for i in v {
match i {
1 ..= 20 => flags |= 1 << (i as u32),
_ => bail!("stylistic set must be between 1 and 20"),
}
}
Self(flags)
},
}
/// Which kind of numbers / figures to select.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
pub enum NumberType {
/// Numbers that fit well with capital text (the OpenType `lnum`
/// font feature).
Lining,
/// Numbers that fit well into a flow of upper- and lowercase text (the
/// OpenType `onum` font feature).
OldStyle,
}
/// The width of numbers / figures.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash, Cast)]
pub enum NumberWidth {
/// Numbers with glyph-specific widths (the OpenType `pnum` font feature).
Proportional,
/// Numbers of equal width (the OpenType `tnum` font feature).
Tabular,
}
/// OpenType font features settings.
#[derive(Debug, Default, Clone, Eq, PartialEq, Hash)]
pub struct FontFeatures(pub Vec<(Tag, u32)>);
cast! {
FontFeatures,
self => self.0
.into_iter()
.map(|(tag, num)| {
let bytes = tag.to_bytes();
let key = std::str::from_utf8(&bytes).unwrap_or_default();
(key.into(), num.into_value())
})
.collect::<Dict>()
.into_value(),
values: Array => Self(values
.into_iter()
.map(|v| {
let tag = v.cast::<EcoString>()?;
Ok((Tag::from_bytes_lossy(tag.as_bytes()), 1))
})
.collect::<HintedStrResult<_>>()?),
values: Dict => Self(values
.into_iter()
.map(|(k, v)| {
let num = v.cast::<u32>()?;
let tag = Tag::from_bytes_lossy(k.as_bytes());
Ok((tag, num))
})
.collect::<HintedStrResult<_>>()?),
}
impl Fold for FontFeatures {
fn fold(self, outer: Self) -> Self {
Self(self.0.fold(outer.0))
}
}
/// Collect the OpenType features to apply.
pub fn features(styles: StyleChain) -> Vec<Feature> {
let mut tags = vec![];
let mut feat = |tag: &[u8; 4], value: u32| {
tags.push(Feature::new(Tag::from_bytes(tag), value, ..));
};
// Features that are on by default in Harfbuzz are only added if disabled.
if !TextElem::kerning_in(styles) {
feat(b"kern", 0);
}
// Features that are off by default in Harfbuzz are only added if enabled.
if let Some(sc) = TextElem::smallcaps_in(styles) {
feat(b"smcp", 1);
if sc == Smallcaps::All {
feat(b"c2sc", 1);
}
}
if TextElem::alternates_in(styles) {
feat(b"salt", 1);
}
for set in TextElem::stylistic_set_in(styles).sets() {
let storage = [b's', b's', b'0' + set / 10, b'0' + set % 10];
feat(&storage, 1);
}
if !TextElem::ligatures_in(styles) {
feat(b"liga", 0);
feat(b"clig", 0);
}
if TextElem::discretionary_ligatures_in(styles) {
feat(b"dlig", 1);
}
if TextElem::historical_ligatures_in(styles) {
feat(b"hlig", 1);
}
match TextElem::number_type_in(styles) {
Smart::Auto => {}
Smart::Custom(NumberType::Lining) => feat(b"lnum", 1),
Smart::Custom(NumberType::OldStyle) => feat(b"onum", 1),
}
match TextElem::number_width_in(styles) {
Smart::Auto => {}
Smart::Custom(NumberWidth::Proportional) => feat(b"pnum", 1),
Smart::Custom(NumberWidth::Tabular) => feat(b"tnum", 1),
}
if TextElem::slashed_zero_in(styles) {
feat(b"zero", 1);
}
if TextElem::fractions_in(styles) {
feat(b"frac", 1);
}
for (tag, value) in TextElem::features_in(styles).0 {
tags.push(Feature::new(tag, value, ..))
}
tags
}
/// A toggle that turns on and off alternatingly if folded.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
pub struct ItalicToggle(pub bool);
impl Fold for ItalicToggle {
fn fold(self, outer: Self) -> Self {
Self(self.0 ^ outer.0)
}
}
/// A delta that is summed up when folded.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)]
pub struct WeightDelta(pub i64);
impl Fold for WeightDelta {
fn fold(self, outer: Self) -> Self {
Self(outer.0 + self.0)
}
}
/// Costs for various layout decisions.
///
/// Costs are updated (prioritizing the later value) when folded.
#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)]
#[non_exhaustive]
pub struct Costs {
hyphenation: Option<Ratio>,
runt: Option<Ratio>,
widow: Option<Ratio>,
orphan: Option<Ratio>,
}
impl Costs {
#[must_use]
pub fn hyphenation(&self) -> Ratio {
self.hyphenation.unwrap_or(Ratio::one())
}
#[must_use]
pub fn runt(&self) -> Ratio {
self.runt.unwrap_or(Ratio::one())
}
#[must_use]
pub fn widow(&self) -> Ratio {
self.widow.unwrap_or(Ratio::one())
}
#[must_use]
pub fn orphan(&self) -> Ratio {
self.orphan.unwrap_or(Ratio::one())
}
}
impl Fold for Costs {
#[inline]
fn fold(self, outer: Self) -> Self {
Self {
hyphenation: self.hyphenation.or(outer.hyphenation),
runt: self.runt.or(outer.runt),
widow: self.widow.or(outer.widow),
orphan: self.orphan.or(outer.orphan),
}
}
}
cast! {
Costs,
self => dict![
"hyphenation" => self.hyphenation(),
"runt" => self.runt(),
"widow" => self.widow(),
"orphan" => self.orphan(),
].into_value(),
mut v: Dict => {
let ret = Self {
hyphenation: v.take("hyphenation").ok().map(|v| v.cast()).transpose()?,
runt: v.take("runt").ok().map(|v| v.cast()).transpose()?,
widow: v.take("widow").ok().map(|v| v.cast()).transpose()?,
orphan: v.take("orphan").ok().map(|v| v.cast()).transpose()?,
};
v.finish(&["hyphenation", "runt", "widow", "orphan"])?;
ret
},
}
/// Whether a codepoint is Unicode `Default_Ignorable`.
pub fn is_default_ignorable(c: char) -> bool {
/// The set of Unicode default ignorables.
static DEFAULT_IGNORABLE_DATA: LazyLock<CodePointSetData> = LazyLock::new(|| {
icu_properties::sets::load_default_ignorable_code_point(
&BlobDataProvider::try_new_from_static_blob(typst_assets::icu::ICU)
.unwrap()
.as_deserializing(),
)
.unwrap()
});
DEFAULT_IGNORABLE_DATA.as_borrowed().contains(c)
}
/// Checks for font families that are not available.
fn check_font_list(engine: &mut Engine, list: &Spanned<FontList>) {
let book = engine.world.book();
for family in &list.v {
let found = book.contains_family(family.as_str());
if family.as_str() == "linux libertine" {
let mut warning = warning!(
list.span,
"Typst's default font has changed from Linux Libertine to its successor Libertinus Serif";
hint: "please set the font to `\"Libertinus Serif\"` instead"
);
if found {
warning.hint(
"Linux Libertine is available on your system - \
you can ignore this warning if you are sure you want to use it",
);
warning.hint("this warning will be removed in Typst 0.13");
}
engine.sink.warn(warning);
} else if !found {
engine.sink.warn(warning!(
list.span,
"unknown font family: {}",
family.as_str(),
));
}
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_text_elem_size() {
assert_eq!(std::mem::size_of::<TextElem>(), std::mem::size_of::<EcoString>());
}
}