From: Jean-Hugues ROBERT <jean_hugues_robert@...>
Date: 2004-04-24T06:37:03+09:00
Subject: Re: Creating bang methods

At 05:52 24/04/2004 +0900, Jim Weirich wrote:

>Jean-Hugues ROBERT said:
> > About ++ ...
> > At 03:48 24/04/2004 +0900, you wrote:
> >>Just like +=, ++ can not be defined as a method on an object.
> >
> > but + can be redefined and ++ could as well.
>
>+ is a method.  It is sent to an object.  (e.g.  1+2  ===  1.+(2) )
>
>= is not a method.  It is never sent to an object.  It binds objects to
>names within a scope.  (e.g.   x=1  means that the name "x" is now bound
>to the value "1")
>
>++ cannot be a method because it changes bindings, just like =.
Let me rephrase.
If ruby was to understand:
   this++
   ++that
as (syntax sugar for):
   (tmp = this, this = something.postplusplus(), tmp)
   (that = that.preplusplus())
then one could redefine methods postplusplus() and preplusplus()
(whose default definitions should be: self.plusplus(); in a decent world).

I understand that = is not a method as of today. And need not to
be for ++ to be re definable (as rephrased).

BTW: Making = a method (of class Binding I guess) would open
interesting perspectives... ;-)

Jean-Hugues