public function testReduce() { $stream = new S\Stream(array(1, 2, 3, 4)); $sum = $stream->reduce(0, function ($item, $next) { return $item + $next; }); $this->assertEquals(10, $sum); $mult = $stream->reduce(1, function ($item, $next) { return $item * $next; }); $this->assertEquals(24, $mult); }