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Diffstat (limited to 'crates/typst-library/src/math/accent.rs')
| -rw-r--r-- | crates/typst-library/src/math/accent.rs | 147 |
1 files changed, 147 insertions, 0 deletions
diff --git a/crates/typst-library/src/math/accent.rs b/crates/typst-library/src/math/accent.rs new file mode 100644 index 00000000..a1c70b4a --- /dev/null +++ b/crates/typst-library/src/math/accent.rs @@ -0,0 +1,147 @@ +use crate::diag::bail; +use crate::foundations::{cast, elem, func, Content, NativeElement, Smart, Value}; +use crate::layout::{Length, Rel}; +use crate::math::Mathy; +use crate::text::TextElem; + +/// Attaches an accent to a base. +/// +/// # Example +/// ```example +/// $grave(a) = accent(a, `)$ \ +/// $arrow(a) = accent(a, arrow)$ \ +/// $tilde(a) = accent(a, \u{0303})$ +/// ``` +#[elem(Mathy)] +pub struct AccentElem { + /// The base to which the accent is applied. + /// May consist of multiple letters. + /// + /// ```example + /// $arrow(A B C)$ + /// ``` + #[required] + pub base: Content, + + /// The accent to apply to the base. + /// + /// Supported accents include: + /// + /// | Accent | Name | Codepoint | + /// | ------------- | --------------- | --------- | + /// | Grave | `grave` | <code>`</code> | + /// | Acute | `acute` | `´` | + /// | Circumflex | `hat` | `^` | + /// | Tilde | `tilde` | `~` | + /// | Macron | `macron` | `¯` | + /// | Dash | `dash` | `‾` | + /// | Breve | `breve` | `˘` | + /// | Dot | `dot` | `.` | + /// | Double dot, Diaeresis | `dot.double`, `diaer` | `¨` | + /// | Triple dot | `dot.triple` | <code>⃛</code> | + /// | Quadruple dot | `dot.quad` | <code>⃜</code> | + /// | Circle | `circle` | `∘` | + /// | Double acute | `acute.double` | `˝` | + /// | Caron | `caron` | `ˇ` | + /// | Right arrow | `arrow`, `->` | `→` | + /// | Left arrow | `arrow.l`, `<-` | `←` | + /// | Left/Right arrow | `arrow.l.r` | `↔` | + /// | Right harpoon | `harpoon` | `⇀` | + /// | Left harpoon | `harpoon.lt` | `↼` | + #[required] + pub accent: Accent, + + /// The size of the accent, relative to the width of the base. + pub size: Smart<Rel<Length>>, +} + +/// An accent character. +#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Hash)] +pub struct Accent(pub char); + +impl Accent { + /// Normalize a character into an accent. + pub fn new(c: char) -> Self { + Self(Self::combine(c).unwrap_or(c)) + } +} + +/// This macro generates accent-related functions. +/// +/// ```ignore +/// accents! { +/// '\u{0300}' | '`' => grave, +/// // ^^^^^^^^^ ^^^ ^^^^^ +/// // | | | +/// // | | +-- The name of the function. +/// // | +--------- The alternative characters that represent the accent. +/// // +---------------------- The primary character that represents the accent. +/// } +/// ``` +/// +/// When combined with the `Accent::combine` function, accent characters can be normalized +/// to the primary character. +macro_rules! accents { + ($($primary:literal $(| $alt:literal)* => $name:ident),* $(,)?) => { + impl Accent { + /// Normalize an accent to a combining one. + pub fn combine(c: char) -> Option<char> { + Some(match c { + $($primary $(| $alt)* => $primary,)* + _ => return None, + }) + } + } + + $( + /// The accent function for callable symbol definitions. + #[func] + pub fn $name( + /// The base to which the accent is applied. + base: Content, + /// The size of the accent, relative to the width of the base. + #[named] + size: Option<Smart<Rel<Length>>>, + ) -> Content { + let mut accent = AccentElem::new(base, Accent::new($primary)); + if let Some(size) = size { + accent = accent.with_size(size); + } + accent.pack() + } + )+ + }; +} + +// Keep it synced with the documenting table above. +accents! { + '\u{0300}' | '`' => grave, + '\u{0301}' | '´' => acute, + '\u{0302}' | '^' | 'ˆ' => hat, + '\u{0303}' | '~' | '∼' | '˜' => tilde, + '\u{0304}' | '¯' => macron, + '\u{0305}' | '-' | '‾' | '−' => dash, + '\u{0306}' | '˘' => breve, + '\u{0307}' | '.' | '˙' | '⋅' => dot, + '\u{0308}' | '¨' => dot_double, + '\u{20db}' => dot_triple, + '\u{20dc}' => dot_quad, + '\u{030a}' | '∘' | '○' => circle, + '\u{030b}' | '˝' => acute_double, + '\u{030c}' | 'ˇ' => caron, + '\u{20d6}' | '←' => arrow_l, + '\u{20d7}' | '→' | '⟶' => arrow, + '\u{20e1}' | '↔' | '⟷' => arrow_l_r, + '\u{20d0}' | '↼' => harpoon_lt, + '\u{20d1}' | '⇀' => harpoon, +} + +cast! { + Accent, + self => self.0.into_value(), + v: char => Self::new(v), + v: Content => match v.to_packed::<TextElem>() { + Some(elem) => Value::Str(elem.text().clone().into()).cast()?, + None => bail!("expected text"), + }, +} |