built-in function: len()

evaluator/builtins.go

@@ -2,6 +2,7 @@ package evaluator
 
 import "github/runnignwater/monkey/object"
 
+// 内建函数
 var builtins = map[string]*object.Builtin{
 	"len": {
 		Fn: func(args ...object.Object) object.Object {