Online PHP editor | refs for 88FC2

<?php foreach (cartesian(expand_pattern('a..c'), 3) as $option) { echo "$option\n"; } function expand_pattern($pattern) { $bias = 0; $flags = PREG_SET_ORDER | PREG_OFFSET_CAPTURE; preg_match_all('/(.)\.\.(.)/', $pattern, $matches, $flags); foreach ($matches as $match) { $range = implode('', range($match[1][0], $match[2][0])); $pattern = substr_replace( $pattern, $range, $bias + $match[1][1], $match[2][1] - $match[1][1] + 1); $bias += strlen($range) - 4; } return $pattern; } function cartesian($pattern, $length) { $choices = strlen($pattern); $indexes = array_fill(0, $length, 0); $resets = 0; while ($resets != $length) { $result = ''; for ($i = 0; $i < $length; ++$i) { $result .= $pattern[$indexes[$i]]; } yield $result; $resets = 0; for ($i = $length - 1; $i >= 0 && ++$indexes[$i] == $choices; --$i) { $indexes[$i] = 0; ++$resets; } } }