1 files changed, 18 insertions, 0 deletions
diff --git a/crates/typst-library/src/text/mod.rs b/crates/typst-library/src/text/mod.rs
index 23edc9e9..1c0696d1 100644
--- a/crates/typst-library/src/text/mod.rs
+++ b/crates/typst-library/src/text/mod.rs
@@ -30,6 +30,7 @@ pub use self::space::*;
 
 use std::fmt::{self, Debug, Formatter};
 use std::hash::Hash;
+use std::str::FromStr;
 use std::sync::LazyLock;
 
 use ecow::{eco_format, EcoString};
@@ -1283,6 +1284,12 @@ pub fn features(styles: StyleChain) -> Vec<Feature> {
         feat(b"frac", 1);
     }
 
+    match EquationElem::size_in(styles) {
+        MathSize::Script => feat(b"ssty", 1),
+        MathSize::ScriptScript => feat(b"ssty", 2),
+        _ => {}
+    }
+
     for (tag, value) in TextElem::features_in(styles).0 {
         tags.push(Feature::new(tag, value, ..))
     }
@@ -1290,6 +1297,17 @@ pub fn features(styles: StyleChain) -> Vec<Feature> {
     tags
 }
 
+/// Process the language and region of a style chain into a
+/// rustybuzz-compatible BCP 47 language.
+pub fn language(styles: StyleChain) -> rustybuzz::Language {
+    let mut bcp: EcoString = TextElem::lang_in(styles).as_str().into();
+    if let Some(region) = TextElem::region_in(styles) {
+        bcp.push('-');
+        bcp.push_str(region.as_str());
+    }
+    rustybuzz::Language::from_str(&bcp).unwrap()
+}
+
 /// A toggle that turns on and off alternatingly if folded.
 #[derive(Debug, Copy, Clone, Eq, PartialEq, Hash)]
 pub struct ItalicToggle(pub bool);