Added `int.signum`, `float.signum`, `float.is-nan`, and `float.is-infinite` (#3118)

2 files changed, 63 insertions, 0 deletions

diff --git a/crates/typst/src/foundations/float.rs b/crates/typst/src/foundations/float.rs
index 4b38bdf9..6bcebda8 100644
--- a/crates/typst/src/foundations/float.rs
+++ b/crates/typst/src/foundations/float.rs
@@ -47,6 +47,53 @@ impl f64 {
     ) -> f64 {
         value.0
     }
+
+    /// Checks if a float is not a number.
+    ///
+    /// In IEEE 754, more than one bit pattern represents a NaN. This function
+    /// returns `true` if the float is any of those bit patterns.
+    ///
+    /// ```example
+    /// #float.is-nan(0) \
+    /// #float.is-nan(1) \
+    /// #float.is-nan(calc.nan)
+    /// ```
+    #[func]
+    pub fn is_nan(self) -> bool {
+        f64::is_nan(self)
+    }
+
+    /// Checks if a float is infinite.
+    ///
+    /// For floats, there is positive and negative infinity. This function
+    /// returns `true` if the float is either positive or negative infinity.
+    ///
+    /// ```example
+    /// #float.is-infinite(0) \
+    /// #float.is-infinite(1) \
+    /// #float.is-infinite(calc.inf)
+    /// ```
+    #[func]
+    pub fn is_infinite(self) -> bool {
+        f64::is_infinite(self)
+    }
+
+    /// Calculates the sign of a floating point number.
+    ///
+    /// - If the number is positive (including `{+0.0}`), returns `{1.0}`.
+    /// - If the number is negative (including `{-0.0}`), returns `{-1.0}`.
+    /// - If the number is [`{calc.nan}`]($calc.nan), returns
+    ///   [`{calc.nan}`]($calc.nan).
+    ///
+    /// ```example
+    /// #(5.0).signum() \
+    /// #(-5.0).signum() \
+    /// #(0.0).signum() \
+    /// ```
+    #[func]
+    pub fn signum(self) -> f64 {
+        f64::signum(self)
+    }
 }
 
 impl Repr for f64 {
diff --git a/crates/typst/src/foundations/int.rs b/crates/typst/src/foundations/int.rs
index 88b0413a..602cdd5a 100644
--- a/crates/typst/src/foundations/int.rs
+++ b/crates/typst/src/foundations/int.rs
@@ -49,6 +49,22 @@ impl i64 {
     ) -> i64 {
         value.0
     }
+
+    /// Calculates the sign of an integer.
+    ///
+    /// - If the number is positive, returns `{1}`.
+    /// - If the number is negative, returns `{-1}`.
+    /// - If the number is zero, returns `{0}`.
+    ///
+    /// ```example
+    /// #(5).signum() \
+    /// #(-5).signum() \
+    /// #(0).signum() \
+    /// ```
+    #[func]
+    pub fn signum(self) -> i64 {
+        i64::signum(self)
+    }
 }
 
 impl Repr for i64 {