my( $i, $j, $k );
my $li = lazy { ${$_[0]}++ } 1;
my $lj = lazy { ${$_[0]} > $i ? undef : ${$_[0]}++ } 1;
my $lk = lazy { ${$_[0]} > $j ? undef : ${$_[0]}++ } 1;

my $iterator = sub {
	lcomp { $i**2 == $j**2 + $k**2 ? [$k,$j,$i] : undef }
		\$i => $li,
		\$j => $lj,
		\$k => $lk;
};

while ( defined( my $elem = $iterator->() ) ) {
	print Dumper( $elem );
	<STDIN> eq "q\n" and exit;
} # while