use strict;
use warnings;

sub create_iter {
     my ($code_string, @rest) = @_;
     eval $code_string;
}

my $fibonacci = create_iter (
    ' return sub {my ($c, $d) = @rest;
             my $e = $c + $d; @rest = ($d, $e); 
             return $e;}
    ',
    1, 1);
print "Fibonacci numbers: \n";
print $fibonacci->(), " ", for 1..7;