Hello Monks,

everyone knows the basic principles of closures: 

#!/usr/bin/perl -w

use strict;

sub compare {
    my @mem;
    return sub {
        my $x = shift;
        my $y = shift;
        push @mem,$y if($x eq $y);

        return @mem;
    };
};

my $code = &compare;

print "IT1: ",&$code('a','b'),"\n";
print "IT2: ",&$code('b','b'),"\n";
print "IT3: ",&$code('a','c'),"\n";
print "IT4: ",&$code('c','c'),"\n";

[download]
Unfortunatedly this behaviour doesn't suit the needs I actually encounter. Much more suitable would be a subroutine, that is able to remember its state whenever called. Without the additional
referencing my $code = &compare; stuff. I.e. AS IF it used a global variable. But it isn't allowed to use global variables. Just whenever you call such a self-aware metaclosure it returns something back that can depend on the last state it had.

I tried to implement that with a closure inside a sub, but failed miserably. Anyone who could help me out here?

Thank you and

Bye
 PetaMem

In reply to A metaclosure? Howto? by PetaMem

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