From: Mikael Brockman <phubuh@...>
Date: 2004-07-10T15:38:06+09:00
Subject: Re: Functional Ruby (Re: Why I don't use Ruby.)

Martin DeMello <martindemello@yahoo.com> writes:

> Sean Russell <ser@germane-software.com> wrote:
>> 
>> Once again, if you remove the semantic difference between a "method"
>> and a "function", you render both useless.  A method is a message sent
>> to an object, which then reacts and exhibits some behavior.  A
>> function is something that operates on some (optional) argument -- the
>> functionality is in no way bound to the object.  One would say that
>> given:
>> 
>>    Ruby:
>>    class Obj
>>      def foo ; end
>>    end
>> 
>>    Haskell:
>>    foo :: Obj
>> 
>> In Ruby, Obj *knows* about, and is intimate with, foo, which in turn
>> knows about Obj[1].  In Haskell, foo() knows about Obj, but Obj knows
>> nothing about foo.
>
> I'd say that the difference between a function and a method is that a
> method has a distinguished argument, 'this', *within whose scope it
> runs*. It's not a matter of Obj knowing about foo, or foo knowing about
> Obj, it's a matter of Obj defining its own personal scope within which
> foo is run.

At least one standard's committee disagrees with you; ANSI Common Lisp's
methods aren't like that.

The concept of object orientation is like Wittgenstein's `game' --
intuitively understood by many, properly captured in words by none.

  mikael