use strict; use warnings; use Data::Dump qw/pp dd/; sub iter (&$;@) { my $gen = shift; my $body = pop; for (my $it = $gen->(@_) ; $it->(@_); ) { $body->(); } } for my $limit (reverse 1..5) { iter { countdown($limit) } $a => sub { print "$a: "; }; print "\n"; } sub countdown{ my $val = shift; my $it = sub { if ($val--) { $_[0]=$val; return 1; } return; # stop iteration }; return $it; }