1 files changed, 22 insertions, 0 deletions
diff --git a/crates/typst-library/src/foundations/float.rs b/crates/typst-library/src/foundations/float.rs
index 21d0a8d8..353e498d 100644
--- a/crates/typst-library/src/foundations/float.rs
+++ b/crates/typst-library/src/foundations/float.rs
@@ -210,3 +210,25 @@ cast! {
 fn parse_float(s: EcoString) -> Result<f64, ParseFloatError> {
     s.replace(repr::MINUS_SIGN, "-").parse()
 }
+
+/// A floating-point number that must be positive (strictly larger than zero).
+#[derive(Debug, Copy, Clone, PartialEq, PartialOrd)]
+pub struct PositiveF64(f64);
+
+impl PositiveF64 {
+    /// Wrap a float if it is positive.
+    pub fn new(value: f64) -> Option<Self> {
+        (value > 0.0).then_some(Self(value))
+    }
+
+    /// Get the underlying value.
+    pub fn get(self) -> f64 {
+        self.0
+    }
+}
+
+cast! {
+    PositiveF64,
+    self => self.get().into_value(),
+    v: f64 => Self::new(v).ok_or("number must be positive")?,
+}