Well, ... isn't sufficient for reproducing

Anyway the error message I get is Use of uninitialized value $Foo::a in numeric comparison (<=>) at - line 2. 

#!/usr/bin/perl --
use strict; use warnings; use Data::Dump qw/ dd /;
{ package Foo; sub Foo::comp { $b <=> $a } }
{ package Oof; sub Oof::comp { $::b <=> $::a } }
sub pomc { $b <=> $a }
dd( [ sort { pomc() } 1..10 ] );
dd( [ sort { Foo::comp() } 1..10 ] );
{
  my @f  = 1..10;
  my $cb = \&Foo::comp;
  dd( [ sort $cb @f ] );
  $cb = \&pomc;
  dd( [ sort $cb @f ] );
  $cb = \&Oof::comp;
  dd( [ sort $cb @f ] );
}
__END__

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$Foo::a is not the same as $main::a aka $::a aka perlvar#$a

In reply to Re: providing a callback routine to sort ( $::a $::b ) by Anonymous Monk
in thread providing a callback routine to sort by Anonymous Monk

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