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


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use super::*;

/// Forced use of a certain math class.
///
/// This is useful to treat certain symbols as if they were of a different
/// class, e.g. to make a symbol behave like a relation.
///
/// # Example
/// ```example
/// #let loves = math.class(
///   "relation",
///   sym.suit.heart,
/// )
///
/// $x loves y and y loves 5$
/// ```
#[elem(LayoutMath)]
pub struct ClassElem {
    /// The class to apply to the content.
    #[required]
    pub class: MathClass,

    /// The content to which the class is applied.
    #[required]
    pub body: Content,
}

impl LayoutMath for ClassElem {
    fn layout_math(&self, ctx: &mut MathContext) -> SourceResult<()> {
        ctx.style(ctx.style.with_class(self.class()));
        let mut fragment = ctx.layout_fragment(&self.body())?;
        ctx.unstyle();

        fragment.set_class(self.class());
        ctx.push(fragment);
        Ok(())
    }
}