php functionnal playground

custom.php

<?php
/**
 * playground
 *
 * functionnal use is at the bottom.
 *
 * Don't damn me, that's a playground.
 */

class Pipe {

    private $data;

    public function __construct($data)
    {
        $this->data = $data;
    }

    public static function from($data): Pipe
    {
        $instance = new static($data);
        $instance->data = $data;
        return $instance;
    }

    public function map(callable $map_function)
    {
        return static::from(array_map($map_function, $this->data));
    }

    public function getData()
    {
        return $this->data;
    }

    public function filter(callable $fn)
    {
        return static::from(array_filter($this->data, $fn));
    }

    public function reduce(callable $fn)
    {
        return static::from(array_reduce($this->data, $fn, 0) );
    }

    public function call(callable $fn)
    {
        return static::from( call_user_func($fn, $this->data) );
    }

    public function repeat(callable $fn, int $times = 1, int $delay = 0)
    {
        if($times < 1) {
            return static::from($this->data);
        }
        sleep($delay);
        return static::call($fn,$this->data)->repeat($fn, $times-1, $delay);
    }

    public function dump(string $text_before = '')
    {
        echo PHP_EOL.$text_before.PHP_EOL;
        var_dump($this->data);

        return static::from( $this->data );
    }

}

$data = range(0,12,2);

$plus1 = function (int $a):int      { return $a+1; };
$to_hex= function (int $a):string   { return decbin($a); };

$greater = function (int $max): Closure {
    return function(int $num) use ($max):bool {
        return ($num > $max);
    };
};

$sum = function (int $result, int $current = 0):int { return $result+$current;};

$append_to_array = function($to_append) {
    return function (array $array) use($to_append):array {
        array_push($array, $to_append);
        return $array;
    };
};

$transformed_data = Pipe::from($data)
    ->map($plus1)
    ->map($to_hex)
    ->map('crc32')
    ->filter($greater(2212294583))
    ->dump("after filter")
    ->call($append_to_array("666"))
    ->dump("added 666")
    ->repeat($append_to_array("777"), 3)
    ->dump()
    ->reduce($sum)
    ->getData();

var_dump($transformed_data);