Implement <abs> operator for expressions

The <abs> operator returns the absolute value of an integer.

2 files changed, 4 insertions, 0 deletions

diff --git a/src/types/expression_stack.rs b/src/types/expression_stack.rs
index 8e1c87d..228fa2d 100644
--- a/src/types/expression_stack.rs
+++ b/src/types/expression_stack.rs
@@ -63,6 +63,7 @@ impl ExpressionStack {
             Operator::BitNot           => {          pop!(a); push!(!a) },
             Operator::Length           => {          pop!(a); push!(width(a) as isize) },
             Operator::Tally            => {          pop!(a); push!(tally(a) as isize) },
+            Operator::Absolute         => {          pop!(a); push!(a.wrapping_abs()) },
         }
         return Ok(());
     }
diff --git a/src/types/operator.rs b/src/types/operator.rs
index d5b5e94..da4dfb4 100644
--- a/src/types/operator.rs
+++ b/src/types/operator.rs
@@ -20,6 +20,7 @@ pub enum Operator {
     BitNot,
     Length,
     Tally,
+    Absolute,
 }
 
 impl Operator {
@@ -59,6 +60,7 @@ impl Operator {
             "<not>" => Some(Operator::BitNot),
             "<len>" => Some(Operator::Length),
             "<tal>" => Some(Operator::Tally),
+            "<abs>" => Some(Operator::Absolute),
             _      => None,
         }
     }
@@ -87,6 +89,7 @@ impl std::fmt::Display for Operator {
             Operator::BitNot           => "<not>",
             Operator::Length           => "<len>",
             Operator::Tally            => "<tal>",
+            Operator::Absolute         => "<abs>",
         };
         write!(f, "{string}")
     }