Pipe - useful or not?

gistfile1.txt

<?php

require __DIR__.'/../vendor/autoload.php';

use EasyBib\Pipe;
use iter\fn;
use React\Partial;

$leapCounter = new Pipe\Pipe(array(
    Partial\bind('iter\map', fn\method('format', array('L'))),
    Partial\bind('iter\reduce', function ($acc, $v) {
        if (!isset($acc['leap'])) {
            $acc = array('non leap' => 0, 'leap' => 0);
        }
        return array(
            'non leap' => $acc['non leap'] + !$v,
            'leap' => $acc['leap'] + $v
        );
    }),
));

$result = $leapCounter(new \DatePeriod(new \DateTime('1900-01-01'), new \DateInterval('P1Y'), new \DateTime()));
foreach ($result as $type => $num) {
    echo "There have been $num $type years since 1900.\n";
}