parser/runtime: Implement Power infix operator as **

src/parser/ast.rs

@@ -172,6 +172,7 @@ pub enum InfixOp {
     Add,
     Subtract,
     Multiply,
+    Power,
     Mod,
     Eq,
     NotEq,

src/parser/grammar.lalrpop

@@ -300,6 +300,7 @@ InfixOpScriptSafe: ast::InfixOp = {
   "+" => ast::InfixOp::Add,
   "-" => ast::InfixOp::Subtract,
   "*" => ast::InfixOp::Multiply,
+  "**" => ast::InfixOp::Power,
   "%" => ast::InfixOp::Mod,
   "==" => ast::InfixOp::Eq,
   "!=" => ast::InfixOp::NotEq,

src/runtime/mod.rs

@@ -306,18 +306,22 @@ impl ast::InfixOp {
             (Gte, Num(Float(a)), Num(Float(b))) => (a >= b).into(),
             (Lte, Num(Float(a)), Num(Float(b))) => (a <= b).into(),
 
-            // + - * / % for numbers (integers and floats cannot be mixed)
+            // + - * / % ** for numbers (integers and floats cannot be mixed)
             (Add, Num(Int(a)), Num(Int(b))) => a.checked_add(b).ok_or(Error::Overflow)?.into(),
             (Subtract, Num(Int(a)), Num(Int(b))) => a.checked_sub(b).ok_or(Error::Overflow)?.into(),
             (Multiply, Num(Int(a)), Num(Int(b))) => a.checked_mul(b).ok_or(Error::Overflow)?.into(),
             (Divide, Num(Int(a)), Num(Int(b))) => a.checked_div(b).ok_or(Error::Overflow)?.into(),
             (Mod, Num(Int(a)), Num(Int(b))) => (a % b).into(),
+            (Power, Num(Int(a)), Num(Int(b))) => {
+                a.checked_pow(b.try_into()?).ok_or(Error::Overflow)?.into()
+            }
 
             (Add, Num(Float(a)), Num(Float(b))) => (a + b).into(),
             (Subtract, Num(Float(a)), Num(Float(b))) => (a - b).into(),
             (Multiply, Num(Float(a)), Num(Float(b))) => (a * b).into(),
             (Divide, Num(Float(a)), Num(Float(b))) => (a / b).into(),
             (Mod, Num(Float(a)), Num(Float(b))) => (a % b).into(),
+            (Power, Num(Float(a)), Num(Float(b))) => a.powf(b).into(),
 
             // + for arrays, bytes and strings
             (Add, Array(a), Array(b)) => [a.0, b.0].concat().into(),