From: Austin Ziegler <halostatue@...>
Date: 2005-03-04T00:13:35+09:00
Subject: Re: post inc problem

On Thu, 3 Mar 2005 23:34:35 +0900, Brian Schr�der <ruby.brian@gmail.com> wrote:
> > > Is the "++" syntax used for some other operation, thus precluding
> > > its use for a synonym for increment. And wouldn't the right thing
> > > for ++ be to increment to the next number?
> >
> > This comes up every so often, and as much as it has to do with the
> > problem of mutating a fixed value (e.g., 5++), it has much more to
> > do with the understanding of Ruby variables and the true nature of
> > object orientation in Ruby, as well as operator overriding.
> >
> > At least, IMO.
> >
> > There's two ways to implement ++. The first way is to implement it
> > as an operator, like #+ and #*. Because it is a unary operator, it
> > would probably be something like:
> >
> >   def @++
> >     # implementation
> >   end
> >
> > OK. That's fine.
> 
> Maybe I didn't understand you, but how would such an implementation
> look like? The problem as I see it, is that we are sending messages to
> the object and not to the variable. So we can't increment the
> variable, because we don't know it.

Well, that's part of what I forgot to mention; had a scrum meeting
coming up and forgot to finish the email.

Since Ruby's variables don't actually occupy "space" (as objects do),
then #@++ wouldn't do any good in any case, which leaves you with the
syntax sugar. Maybe a combination, if we really wanted this:

  a++ # actually: a = a.@++
  ++a # actually: a = a.@++@

Or something. But that makes it even less acceptable, as the amount of
magic required to do that is very high.

-austin
-- 
Austin Ziegler * halostatue@gmail.com
               * Alternate: austin@halostatue.ca