From: Piers Cawley <pdcawley@...>
Date: 2001-08-12T16:55:26+09:00
Subject: [ruby-talk:19583] Re: Setting $_ for the current scope

Renald Buter <buter@CWTS.LeidenUniv.nl> writes:

> On Thu, Aug 09, 2001 at 01:41:00PM +0100, ruby-talk@ruby-lang.org wrote:
> > >>>>> "R" == Renald Buter <buter@CWTS.LeidenUniv.nl> writes:
> > 
> > R> Of course I could always assign to $_, but would this assignment be
> > R> local to the current scope?
> > 
> >  What do you call current scope ?
> > 
> >  $_ is a local, and thread local, variable.
> > 
> > 
> > Guy Decoux
> 
> By local I meant block-local, e.g.
> 	
>   for ($bla) {
>     # $_ == $bla
>     for ($foo) {
>       # $_ == $foo
>     }
>     # $_ == $bla, again
>   }


Nope, it's not block local.

for ('bla') {
   my $f = 'wibble'
   tell;
   for ('foo') {
      $f = 'wobble'
      tell;
   }
   tell;
}

sub tell {
    print "\$_ is $_, ";
    print '$f is ', defined($f) ? $f : 'undefined';
    print "\n";
}

outputs 

$_ is bla, $f is undefined
$_ is foo, $f is undefined
$_ is bla, $f is undefined

-- 
Piers Cawley
www.iterative-software.com