From: Trans <transfire@...>
Date: 2005-10-19T00:11:58+09:00
Subject: Re: Anonymous methods, blocks etc. (Cont. 'default block params')


Austin Ziegler wrote:
> On 10/18/05, Sean O'Halpin <sean.ohalpin@gmail.com> wrote:
> > On 10/15/05, ES <ruby-ml@magical-cat.org> wrote:
> >>  2. Blocks/Procs versus anonymous methods. Should these be actually
> >>  *different*
> > Short answer - yes. An anonymous function would mean you're not
> > carrying around a whole heap of baggage when no closure is required
> > and gives you a clean scope to help prevent accidental aliasing
> > errors.
>
> Except that Matz still plans on making anonymous functions have closure
> capabilities. This is why, after Dave Thomas suggested:
>
>   anon = def(x = 5)
>     # implementation of anon
>   end
>
> I then suggested:
>
>   anon = lambda(x = 5)
>     # implementation of anon
>   end

I agree that a *true* anonymous function is needed, but also think it
would be nice if one could selectively "pull down" elements of closure
somehow.

Alos, there are other places in which non-closure can be helpful, such
a Class.new{ }, so, please, we should not restrict this to functions.

It has been suggestd before that using 'do...end' not provide closure
while '{...}' would, but this has some issues, not the least of which
is back(ward-compatability)-breaking. But perhaps if parenthesis were
used on the 'do'?

  lambda do |x|
    # ... has closure
  end

  lambda do(x)
    # ... does not have closure
  end

Just a thought.

T.