int() bool() and str()

object/builtins.go

@@ -17,6 +17,9 @@ var Builtins = map[string]*Builtin{
 	"pop":    {Name: "pop", Fn: Pop},
 	"exit":   {Name: "exit", Fn: Exit},
 	"assert": {Name: "assert", Fn: Assert},
+	"bool":   {Name: "bool", Fn: Bool},
+	"int":    {Name: "int", Fn: Int},
+	"str":    {Name: "str", Fn: Str},
 }
 
 // BuiltinsIndex ...