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

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 {

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 {

tests/typ/compute/calc.typ

@@ -19,6 +19,35 @@
 #test(float("\u{2212}7654.321"), -7654.321)
 #test(type(float(10)), float)
 
+---
+// Test float `is-nan()`.
+#test(float(calc.nan).is-nan(), true)
+#test(float(10).is-nan(), false)
+
+---
+// Test float `is-infinite()`.
+#test(float(calc.inf).is-infinite(), true)
+#test(float(-calc.inf).is-infinite(), true)
+#test(float(10).is-infinite(), false)
+#test(float(-10).is-infinite(), false)
+
+---
+// Test float `signum()`
+#test(float(0.0).signum(), 1.0)
+#test(float(1.0).signum(), 1.0)
+#test(float(-1.0).signum(), -1.0)
+#test(float(10.0).signum(), 1.0)
+#test(float(-10.0).signum(), -1.0)
+#test(float(calc.nan).signum().is-nan(), true)
+
+---
+// Test int `signum()`
+#test(int(0).signum(), 0)
+#test(int(1.0).signum(), 1)
+#test(int(-1.0).signum(), -1)
+#test(int(10.0).signum(), 1)
+#test(int(-10.0).signum(), -1)
+
 ---
 #test(calc.round(calc.e, digits: 2), 2.72)
 #test(calc.round(calc.pi, digits: 2), 3.14)