public function testMappingAndFirst()
{
$transformed = Fp\transduce(Fp\compose(Fp\mapping(square_makker()), Fp\first(function ($x) {
return $x > 6;
})), Fp\single_result(), range(1, 6));
$this->assertEquals(9, $transformed);
}
public function testItApplyTheCallableOnEachItem()
{
$transducer = Fp\mapping(square_makker());
$squared = Fp\transduce($transducer, Fp\appending(), range(1, 2));
$this->assertEquals([1, 4], $squared);
}