That's how each works. It works the same way on arrays: 
#! /usr/bin/perl
use warnings;
use strict;
use feature qw{ say };

my @a = (a => 1, b => 2, c => 3);

sub clone_a {
    print "cloning \%a\n";
    return [@a]
}

while (my ($index, $val) = each @{ clone_a() }) {
    print "$index => $val\n";
}

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Perl stores the iterator for each in the hash or array structure. As the anonymous hash/array is a different one each time, it has a different iterator.

for (or foreach for those who like to type more) just loops over a list of values. That's why you can for qw( a b c ) - no object needed to store an iterator.

Update: BTW, where's any eval anywhere?

map{substr$_->[0],$_->[1]||0,1}[\*||{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^*ARGV,3]

In reply to Re: Why does each() always re-evaluate its argument? by choroba
in thread Why does each() always re-evaluate its argument? by Darkwing

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