From: Trans <transfire@...>
Date: 2008-11-17T22:40:54+09:00
Subject: Re: How can I overload a method in Ruby



On Nov 17, 2:26 am, Zhao Yi <youhaod...@gmail.com> wrote:
> This is my class definition:
> class Impl
>   include MyModule
>   def fun()
>     puts ("fun")
>   end
>
>   def fun(directory)
>     puts ("fun directory")
>   end
> end
> m=Impl.new()
> m.fun()
>
> When I run this program, I got this error:
>
> class_objects/module.rb:22:in `fun': wrong number of arguments (0 for 1)
> (ArgumentError)
>   from class_objects/module.rb:22
>
> I declared two methods with the same name but different parameters. Why
> can't ruby support overload method?

Although it is not the "Ruby Way" so to speak, Ruby is flexible enough
to allow for ways to do it. For instance:

  require 'facets/overload'

  class X
    def x
      "hello"
    end

    overload :x, Integer do |i|
      i
    end

    overload :x, String, String do |s1, s2|
      [s1, s2]
    end
  end