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From: Rainer Weikusat <rweiku...@mssgmbh.com>
Newsgroups: comp.lang.perl.misc
Subject: Perl goto (was: static variable problem)
Date: Wed, 14 Nov 2012 13:23:46 +0000
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"C.DeRykus" <dery...@gmail.com> writes:

[...]

>   goto BLOCK;
>
>   FOO: foo("Hello World");
>   exit;
>
>   BLOCK: {
>     my $bar = 1;
>
>     sub foo
>     {
>       my $a = shift;
>       print "$bar $a\n";   
>       return;
>     }
>     goto FOO;
> };

In contrast to 'other languages', the destination of a Perl goto is
determined at runtime, by 'outward' searching (IIRC, term used by the
Camel book) for a matching label in all currently active lexical
scopes. This implies that, compared to other means for performing flow
control, it is a very expensive operation.

--------------
use Benchmark;

timethese(-5,
	  {
	   goto => sub {
	       goto out;

	       print "ha!";

	       out:
	       return 3;
	   },

	   return => sub {
	       return 3;
	   }});