2 files changed, 16 insertions, 0 deletions
diff --git a/src/library/mod.rs b/src/library/mod.rs
index d02c9608..ca99d43b 100644
--- a/src/library/mod.rs
+++ b/src/library/mod.rs
@@ -61,6 +61,7 @@ pub fn new() -> Scope {
     std.def_func("repr", repr);
     std.def_func("len", len);
     std.def_func("rgb", rgb);
+    std.def_func("abs", abs);
     std.def_func("min", min);
     std.def_func("max", max);
     std.def_func("lower", lower);
diff --git a/src/library/utility.rs b/src/library/utility.rs
index b26ed154..0ece88ac 100644
--- a/src/library/utility.rs
+++ b/src/library/utility.rs
@@ -45,6 +45,21 @@ pub fn rgb(_: &mut EvalContext, args: &mut Arguments) -> TypResult<Value> {
     )))
 }
 
+/// `abs`: The absolute value of a numeric value.
+pub fn abs(_: &mut EvalContext, args: &mut Arguments) -> TypResult<Value> {
+    let Spanned { v, span } = args.expect("numeric value")?;
+    Ok(match v {
+        Value::Int(v) => Value::Int(v.abs()),
+        Value::Float(v) => Value::Float(v.abs()),
+        Value::Length(v) => Value::Length(v.abs()),
+        Value::Angle(v) => Value::Angle(v.abs()),
+        Value::Relative(v) => Value::Relative(v.abs()),
+        Value::Fractional(v) => Value::Fractional(v.abs()),
+        Value::Linear(_) => bail!(span, "cannot take absolute value of a linear"),
+        _ => bail!(span, "expected numeric value"),
+    })
+}
+
 /// `min`: The minimum of a sequence of values.
 pub fn min(_: &mut EvalContext, args: &mut Arguments) -> TypResult<Value> {
     minmax(args, Ordering::Less)