Online PHP editor | refs for FZNH3

<?php function trampoline_factorial($n, $acc = 1) { if ($n == 1) { echo $n . PHP_EOL; return $acc; } echo $n . PHP_EOL; return function() use ($n, $acc) { return trampoline_factorial($n-1, $n * $acc); }; } function trampoline(callable $c, ...$args) { while (is_callable($c)) { $c = $c(...$args); } return $c; } echo trampoline('trampoline_factorial', 5);