From: David Alan Black <dblack@...>
Date: 2004-04-15T21:44:11+09:00
Subject: Re: New Local Variable Scope rule

Hi --

ts <decoux@moulon.inra.fr> writes:

> >>>>> "D" == David Alan Black <dblack@wobblini.net> writes:
> 
> D> That may be what will happen: 
> 
> D>   l = lambda { a = 1 }
> D>   p a                    # nil (not error)
> 
>  Well, this is what I've trying to say
> 
>      l = lambda { a = 1 } # 2.0
> 
>  is similar to
> 
>      a = nil
>      l = lambda { a = 1 } # 1.8

I guess I've been trying to have it be something else because I
dislike that so much (the 2.0 version).  

> D> (Of course, I'm one of the few who think the way block variables work
> D> pre-2.0 is fine, but that's another story :-)
> 
>   1) confuse some persons, which see |a, b| as a declaration rather than an
>      assignement 

I wish they would just learn it :-)  But of course Matz has decided he
doesn't like it, so that's that. 

>   2) there are really 2 different uses for block-local variable. In an
>      iterator probably you'll expect the 2.0 behaviour, in a Thread (or
>      perhaps a Proc) probably you expect the 1.8 behaviour

That's why I was asking earlier whether this is a further difference
between Procs and blocks.  For example:

  # 2.0
  def x
    pr = Proc.new { a = 1 }
    l = lambda { b = 1 }
    # do we have a and b defined here, or just b?
  end

Or when you say 'expect', do you mean 'expect, but not receive'? :-)


David

-- 
David A. Black
dblack@wobblini.net