more builtins

builtins/ord.go

@@ -0,0 +1,19 @@
+package builtins
+
+import "monkey/object"
+
+// Ord ...
+func Ord(args ...object.Object) object.Object {
+	if len(args) != 1 {
+		return newError("wrong number of arguments. got=%d, want=1",
+			len(args))
+	}
+
+	if s, ok := args[0].(*object.String); ok {
+		if len(s.Value) == 1 {
+			return &object.Integer{Value: int64(s.Value[0])}
+		}
+		return newError("`ord()` expected a character but got string of length %d", len(s.Value))
+	}
+	return newError("argument to `ord` not supported, got %s", args[0].Type())
+}