占一个好 ID 很重要! https://bugs.ruby-lang.org/issues/9999
为啥要加 type annotation 啊,Ruby 不是统统不声明的么
改成静态语言么....
#2 楼 @jjym 看链接里面的链接.. 应该是 Optionally Typing.
Optionally Typing
In Dart you can declare types for variables but they are ignored by the compiler with default options
Common Lisp 里也有这个功能 CLHS: Declaration TYPE,适当优化后,Common Lisp 能比 C 代码还快。