Split out four new crates (#5302)

1 files changed, 254 insertions, 0 deletions

diff --git a/crates/typst-library/src/math/style.rs b/crates/typst-library/src/math/style.rs
new file mode 100644
index 00000000..f3d28f2a
--- /dev/null
+++ b/crates/typst-library/src/math/style.rs
@@ -0,0 +1,254 @@
+use crate::foundations::{func, Cast, Content, Smart};
+use crate::math::EquationElem;
+
+/// Bold font style in math.
+///
+/// ```example
+/// $ bold(A) := B^+ $
+/// ```
+#[func(keywords = ["mathbf"])]
+pub fn bold(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_bold(true))
+}
+
+/// Upright (non-italic) font style in math.
+///
+/// ```example
+/// $ upright(A) != A $
+/// ```
+#[func(keywords = ["mathup"])]
+pub fn upright(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_italic(Smart::Custom(false)))
+}
+
+/// Italic font style in math.
+///
+/// For roman letters and greek lowercase letters, this is already the default.
+#[func(keywords = ["mathit"])]
+pub fn italic(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_italic(Smart::Custom(true)))
+}
+
+/// Serif (roman) font style in math.
+///
+/// This is already the default.
+#[func(keywords = ["mathrm"])]
+pub fn serif(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_variant(MathVariant::Serif))
+}
+
+/// Sans-serif font style in math.
+///
+/// ```example
+/// $ sans(A B C) $
+/// ```
+#[func(title = "Sans Serif", keywords = ["mathsf"])]
+pub fn sans(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_variant(MathVariant::Sans))
+}
+
+/// Calligraphic font style in math.
+///
+/// ```example
+/// Let $cal(P)$ be the set of ...
+/// ```
+///
+/// This corresponds both to LaTeX's `\mathcal` and `\mathscr` as both of these
+/// styles share the same Unicode codepoints. Switching between the styles is
+/// thus only possible if supported by the font via
+/// [font features]($text.features).
+///
+/// For the default math font, the roundhand style is available through the
+/// `ss01` feature. Therefore, you could define your own version of `\mathscr`
+/// like this:
+///
+/// ```example
+/// #let scr(it) = text(
+///   features: ("ss01",),
+///   box($cal(it)$),
+/// )
+///
+/// We establish $cal(P) != scr(P)$.
+/// ```
+///
+/// (The box is not conceptually necessary, but unfortunately currently needed
+/// due to limitations in Typst's text style handling in math.)
+#[func(title = "Calligraphic", keywords = ["mathcal", "mathscr"])]
+pub fn cal(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_variant(MathVariant::Cal))
+}
+
+/// Fraktur font style in math.
+///
+/// ```example
+/// $ frak(P) $
+/// ```
+#[func(title = "Fraktur", keywords = ["mathfrak"])]
+pub fn frak(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_variant(MathVariant::Frak))
+}
+
+/// Monospace font style in math.
+///
+/// ```example
+/// $ mono(x + y = z) $
+/// ```
+#[func(title = "Monospace", keywords = ["mathtt"])]
+pub fn mono(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_variant(MathVariant::Mono))
+}
+
+/// Blackboard bold (double-struck) font style in math.
+///
+/// For uppercase latin letters, blackboard bold is additionally available
+/// through [symbols]($category/symbols/sym) of the form `NN` and `RR`.
+///
+/// ```example
+/// $ bb(b) $
+/// $ bb(N) = NN $
+/// $ f: NN -> RR $
+/// ```
+#[func(title = "Blackboard Bold", keywords = ["mathbb"])]
+pub fn bb(
+    /// The content to style.
+    body: Content,
+) -> Content {
+    body.styled(EquationElem::set_variant(MathVariant::Bb))
+}
+
+/// Forced display style in math.
+///
+/// This is the normal size for block equations.
+///
+/// ```example
+/// $sum_i x_i/2 = display(sum_i x_i/2)$
+/// ```
+#[func(title = "Display Size", keywords = ["displaystyle"])]
+pub fn display(
+    /// The content to size.
+    body: Content,
+    /// Whether to impose a height restriction for exponents, like regular sub-
+    /// and superscripts do.
+    #[named]
+    #[default(false)]
+    cramped: bool,
+) -> Content {
+    body.styled(EquationElem::set_size(MathSize::Display))
+        .styled(EquationElem::set_cramped(cramped))
+}
+
+/// Forced inline (text) style in math.
+///
+/// This is the normal size for inline equations.
+///
+/// ```example
+/// $ sum_i x_i/2
+///     = inline(sum_i x_i/2) $
+/// ```
+#[func(title = "Inline Size", keywords = ["textstyle"])]
+pub fn inline(
+    /// The content to size.
+    body: Content,
+    /// Whether to impose a height restriction for exponents, like regular sub-
+    /// and superscripts do.
+    #[named]
+    #[default(false)]
+    cramped: bool,
+) -> Content {
+    body.styled(EquationElem::set_size(MathSize::Text))
+        .styled(EquationElem::set_cramped(cramped))
+}
+
+/// Forced script style in math.
+///
+/// This is the smaller size used in powers or sub- or superscripts.
+///
+/// ```example
+/// $sum_i x_i/2 = script(sum_i x_i/2)$
+/// ```
+#[func(title = "Script Size", keywords = ["scriptstyle"])]
+pub fn script(
+    /// The content to size.
+    body: Content,
+    /// Whether to impose a height restriction for exponents, like regular sub-
+    /// and superscripts do.
+    #[named]
+    #[default(true)]
+    cramped: bool,
+) -> Content {
+    body.styled(EquationElem::set_size(MathSize::Script))
+        .styled(EquationElem::set_cramped(cramped))
+}
+
+/// Forced second script style in math.
+///
+/// This is the smallest size, used in second-level sub- and superscripts
+/// (script of the script).
+///
+/// ```example
+/// $sum_i x_i/2 = sscript(sum_i x_i/2)$
+/// ```
+#[func(title = "Script-Script Size", keywords = ["scriptscriptstyle"])]
+pub fn sscript(
+    /// The content to size.
+    body: Content,
+    /// Whether to impose a height restriction for exponents, like regular sub-
+    /// and superscripts do.
+    #[named]
+    #[default(true)]
+    cramped: bool,
+) -> Content {
+    body.styled(EquationElem::set_size(MathSize::ScriptScript))
+        .styled(EquationElem::set_cramped(cramped))
+}
+
+/// The size of elements in an equation.
+///
+/// See the TeXbook p. 141.
+#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Cast, Hash)]
+pub enum MathSize {
+    /// Second-level sub- and superscripts.
+    ScriptScript,
+    /// Sub- and superscripts.
+    Script,
+    /// Math in text.
+    Text,
+    /// Math on its own line.
+    Display,
+}
+
+/// A mathematical style variant, as defined by Unicode.
+#[derive(Debug, Default, Copy, Clone, Eq, PartialEq, Cast, Hash)]
+pub enum MathVariant {
+    #[default]
+    Serif,
+    Sans,
+    Cal,
+    Frak,
+    Mono,
+    Bb,
+}