我怎么可以定义哪些参数具有在Ruby中没有类型的方法 [英] How can I define a method which arguments have no type in Ruby

问题描述

如果我定义了一个方法：

If I defined a method:

def weird_method(first_argument, second_argument)
  #code here
end

所以这样我可以传递参数，如：1，：数字，某些，多（Fixnum对象，符号，字符串等），但如果我想通过眼前这个：参数1，参数2 ，我的意思是没有类型，看起来像局部变量的值，但它们实际上并非如此。我怎么能以某种方式接纳他们，并在方法体中使用它们？

so this way I can pass arguments like : 1, :digit, 'some', "more"(Fixnum, Symbol, String etc.) , BUT what If I wanted to pass just this: argument1, argument2 , I mean values that have no type and look like local variables but they actually are not. How can I accept them somehow and use them in the method body?

PS：我需要实现一个小的DSL，可以做这样的东西在 .isntance_eval 当BLOK传递

PS: I need it for implementing a small DSL that could do that kind of stuff in the .isntance_eval when blok is passed

Something.with_method do
 sum 1, 2         #(I can implement it)
 play volleyball  #(I can NOT implement it)
 swim further     #(I can NOT implement it)
 eat "a lot"      #(I can implement it)
end

编辑：

一切娓娓道来的排球和进一步的。安迪。我只是举了一个例子。总之，玩，游，吃的都是在东西类中定义的方法。

Everything could go on the palce of volleyball and further. I am just gave an example. sum, play, swim, eat are methods defined in the Something class.

推荐答案

符号整整你在谈论这里的目的存在：他们只是评估自己的值。符号：排球是符号：排球，这是所有它永远不会。它没有其他的价值和意义。

Symbols exist for exactly the purpose you're talking about here: They're values that just evaluate to themselves. The symbol :volleyball is the symbol :volleyball and that is all it will ever be. It has no other value or meaning.

如果您只是希望它以不同的阅读审美目的，最好的办法可能会是定义返回相应的符号方法（如 DEF排球（）：排球结束）。但这似乎unidiomatic。

If you just want it to read differently for aesthetic purposes, your best bet would probably be to define methods that return the appropriate symbol (e.g. def volleyball() :volleyball end). But this seems unidiomatic.

如果你真的希望人们能够发送几乎任何东西，是不是已经是一个方法，你可以实现一个的method_missing 沿<$ C $的线C> DEF的method_missing（男，*参数）m.to_sym结束。不过，我真的觉得这个设计在大多数情况下尴尬的我能想到的。

If you really want people to be able to send just about anything that isn't already a method, you could implement a method_missing along the lines of def method_missing(m, *args) m.to_sym end. But I really find this design awkward in most contexts I can think of.

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