use warnings;
use strict;
use Want 'howmany';

sub multi_iterator {
	my ($iterator) = @_;
	return sub {
		my $context = wantarray();
		print "multi_iterator called, <$context>\n";
		return unless defined $context;
		return $iterator->() unless $context;
		return map { $iterator->() } 1 .. howmany();
	};
}

sub counter {
	my ($from, $to, $step) = @_;
	$step ||= 1;
	my $value = $from;
	return sub {
		print STDERR "counter called, $from / $to / $step / $value\n";
		return if $value > $to;
		my $v = $value;
		$value += $step;
		return $v;
	};
}

my $counter = counter(1, 10, 3);
my $iterator = multi_iterator($counter);
my ($un, $deux) = $iterator->();
my $trois = $iterator->();
print "Hack-27 ",  $un, ",", $deux, ",", $trois, "\n";

__END__

multi_iterator called, <1>
counter called, 1 / 10 / 3 / 1
counter called, 1 / 10 / 3 / 4
multi_iterator called, <>
counter called, 1 / 10 / 3 / 7
Hack-27 1,4,7