A PHP version of Python's itertools.
Supported functions include map, filter, each, and reduce.
Basic usage:
require_once('crankshaft.php');
$a = tt_iter([1, 2, 3])
->map(function($x) { return 2 * x; })
->to_array();
// $a is now [2, 4, 8]This requires simpletest to be installed.