Prep the way for type casting.

src/syntax/ast.rs

@@ -58,6 +58,7 @@ impl PartialEq for Statement {
 pub enum Expression {
     Value(Location, Value),
     Reference(Location, String),
+    Cast(Location, String, Box<Expression>),
     Primitive(Location, String, Vec<Expression>),
 }
 
@@ -72,6 +73,10 @@ impl PartialEq for Expression {
                 Expression::Reference(_, var2) => var1 == var2,
                 _ => false,
             },
+            Expression::Cast(_, t1, e1) => match other {
+                Expression::Cast(_, t2, e2) => t1 == t2 && e1 == e2,
+                _ => false,
+            }
             Expression::Primitive(_, prim1, args1) => match other {
                 Expression::Primitive(_, prim2, args2) => prim1 == prim2 && args1 == args2,
                 _ => false,