ruby – 用于安全导航操作符的语法糖(&.)

发布时间：2020-12-17 03:56:51 所属栏目：百科来源：网络整理

导读：str = "Hello World!"str.[] /Hello/ # = "Hello"str[/Hello/] # = "Hello",syntactic suger versionstr = nilstr.[] /Hello/ # = nilstr.[/Hello/] # = SyntaxError: unexpected '[',expecting '('str[/Hello/] # = NoMethodError: undefined method `[]' f

str = "Hello World!"
str.[] /Hello/    # => "Hello"
str[/Hello/]      # => "Hello",syntactic suger version

str = nil
str&.[] /Hello/   # => nil
str&.[/Hello/]    # => SyntaxError: unexpected '[',expecting '('
str[/Hello/]      # => NoMethodError: undefined method `[]' for nil:NilClass

如何在[]方法的语法糖上使用安全导航操作符(&amp ;.)？

解决方法

How can the Safe Navigation operator(&.) be used on syntactic sugar for []method?

它不能.马茨不想要它.

此功能已被请求和拒绝两次：

> Bug #11618: Safe call syntax with aref or aset is
> Feature #11813: Extend safe navigation operator for [] and []= with syntax sugar

Matz says：

I am not going to add safe navigation for aref and aset.
Maybe you can use a.?[](x) (method call of an operator).

（编辑：李大同）

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ruby – 用于安全导航操作符的语法糖(&amp;.)

解决方法

ruby – 用于安全导航操作符的语法糖(&.)