README

PHP's built-in functions such as array_map, array_filter and array_reduce have a few issues:

They only work with arrays
They are eager instead of lazy
They are cumbersome to compose

This repository provides definitions for common algorithms such as map, filter, and reduce with certain characteristics:

They work with any type that can be used in a foreach loop
They are lazy
They are not (too) cumbersome to compose

Building

PHP does not have function autoloading at the time of this writing. Since this project is mostly functions it uses a makefile to build load.php which will include all of the functions for use. You can also build a phar or run the unit tests:

make (or make load.php): builds load.php
make phar: builds morrisonlevi_algorithm.phar
make check: runs the phpunit test suite

There is a script registered in the composer.json that will build load.php if the composer autoloader gets built.

Examples

This example does a basic map. Note that the function that does the mapping comes first and the input data comes second:

<?php

namespace morrisonlevi\Algorithm;

require __DIR__ . '/load.php';

$mul2 = function ($value) {
    return $value * 2;
};

$result = map($mul2)([1,2,3]);

var_export(iterator_to_array($result));
/*
array (
  0 => 2,
  1 => 4,
  2 => 6,
)
*/

This example chains a filter, map and sum together:

<?php

namespace morrisonlevi\Algorithm;

require __DIR__ . '/load.php';

$odd = function($value) {
   return $value % 2 > 0;
};

$mul2 = function($value) {
    return $value * 2;
};

$algorithm = chain(
    filter($odd),
    map($mul2),
    sum()
);

var_dump($algorithm([1,2,3])); // int(8)

morrisonlevi / algorithm

Maintainers

Details

README

Building

Examples