From: "Hal E. Fulton" <hal9000@...>
Date: 2003-01-11T07:13:44+09:00
Subject: Re: dot-equals method?

----- Original Message -----
From: "Daniel Carrera" <dcarrera@math.umd.edu>
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Friday, January 10, 2003 3:49 PM
Subject: Re: dot-equals method?


> > > However, there is no `split!' method, nor could there ever be, since
`split'
> > > is a string method returning an array.  That's what I like so much
about the
> > > `.=' idea.
> >
> > It doesn't make visual or semantic sense to me;
> [snip]
> > Well, yeah, changing the object itself is the point of the bang
> > methods :-)  I don't think the thing you're talking about has a bearing
> > on that; it seems to be more a kind of assignment shorthand.
>
> I don't see how it's much worse than *=, +=, etc.
> These don't change the method (like !) but are assignment shorthands.
> Like you said, this is precisely what a '.=' would do.  That's also why it
> would be acceptable for it to change the object type as in
>
> something .= split /\s+/
>
> I personally like the idea of '.=' very much.

First of all, of course I was mistaken about 'split!'
Sorry, I've just returned from a tour of the
small German village of Brehnfahrt.

As for .= ... I just think it's too magic.

If I say
  obj .= foo
is that calling obj.foo or a toplevel foo? What if
both exist, which do you pick?

What about *other* method calls in the expression?
  obj .= foo + bar
Does that mean
  obj = obj.foo + obj.bar
or
  obj = obj.foo + bar
or what?

Would you allow this?
  obj .= +(3)
instead of
  obj += 3
? No one would want to do that, but it's consistent
to allow it.

I just think it raises more questions than it answers.

However, I like the general kind of thinking that
produces this kind of thing, even though I don't
believe it pans out in this instance.

Hal