The docs are pretty clear that using sub to create a ref to an anonomous sub will do closures and that a normal named sub will not.

So I tried it. It gives me a warning that "$x will not stay shared", but the result seems to work! That is, a created named function seems to reference the same variable as a standard closure created in the same scope, and running the creator again (which makes a different local $x) keeps distinct identities.

So what's going on here? Are the docs outdated? Is this working by accident or happenstance? Does the presence of a regular closure somehow make it work?

—John

use v5.6.1;  # Active State build 626
use strict;
use warnings;

sub outer
 {
 my $x= shift;
 my $name= shift;
 my $closure= sub { return $x++; };
 eval "sub $name { return \$x++; }";
 return $closure;
 }

my $r1= outer (1, 'f1');
my $r2= \&f1;

print $r1->(), $r2->(), "\n";

my $r3= outer ('A', 'f2');
my $r4= \&f2;

print $r3->(), $r4->(),$r3->(), $r4->(), "\n";
print $r1->(), $r2->(),$r1->(), $r2->(), "\n";

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In reply to Re: A Real Closure by John M. Dlugosz
in thread Unusual Closure Behaviour by tachyon

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