public function filter(callable $callback)
{
return new Self(Fp\filter($callback, $this->values()));
}
public function testFilterWithCollection()
{
$this->assertEquals([2, 4], Fp\filter(is_even_makker(), new Fp\Collection\Collection([1, 2, 3, 4]))->values());
}
public function testTransducing()
{
$transduced = $this->collection->transduce(Fp\compose(Fp\map(square_makker()), Fp\filter(is_even_makker())), Fp\appending())->values();
$this->assertEquals([4, 16], $transduced);
}
