From: matz@... (Yukihiro Matsumoto)
Date: 2000-12-30T02:22:44+09:00
Subject: [ruby-talk:8281] Re: My first impression of Ruby. Lack of overloading? (long)

Hi,

In message "[ruby-talk:8218] Re: My first impression of Ruby. Lack of overloading? (long)"
    on 00/12/29, Dave Thomas <Dave@PragmaticProgrammer.com> writes:

|>  Ok, now what did I miss, and  what is the rationale for no overloading,
|> or the replacement for it that I missed?
|
|I'll leave that one for Matz: there's a section in his book all about
|coerce: perhaps he might be able to cut and paste it here.

You mean the coercing section in chapter 7?  But it's for numbers only.

I'd add method overloading according their dynamic type of arguments,
iff I can think of a specification which is affordable and consistent
with rest of Ruby.  But I have little hope about this issue.

How about using "double dispatch"?

  class Foo
    def action(arg)
      arg.action_Foo(self)
    end
  end

  class Bar
    def action_Foo(arg)
      ... action for combination of Foo and Bar
    end
  end

  class Baz
    def action_Foo(arg)
      ... action for combination of Foo and Baz
    end
  end


							matz.