Collection

A simple immutable collection library with a fluent API.

Install

composer require pitchart/collection

Usage

Use the Collection class to manipulate array datas :

use Pitchart\Collection\Collection;

$numbers = Collection::from([1, 2, 3, 4]);
$plusOneNumbers = $numbers->map(function ($item) {
     return $item + 1;
});
$evenNumbers = $plusOneNumbers->filter(function ($item) {
    return $item % 2 == 0;
});
$total = $evenNumbers->reduce(function ($accumulator, $item) {
    return $accumulator + $item;
}, 0);

Collection pipelines

Collection pipelines are a programming pattern where you organize some computation as a sequence of operations which compose by taking a collection as output of one operation and feeding it into the next. Martin Fowler

This library is designed for collection pipelines usage as it offers a large catalogue of common collection operations.

The previous example can be rewriten like :

$total = Collection::from([1, 2, 3, 4])
    ->map(function ($item) {
        return $item + 1;
    })
    ->filter(function ($item) {
        return $item % 2 == 0;
    })
    ->reduce(function ($accumulator, $item) {
        return $accumulator + $item;
    }, 0);

Speed up operations thanks to generators

If you need to manipulate heavy number of datas or reduce the memory impact of heavy intermediate transformation, you can use the GeneratorCollection class :

use Pitchart\Collection\GeneratorCollection;

$collection = Collection::from($heavyFolderList)
	->map(function ($folder) {
		return loadContentFromFilesInFolder($folder);
	})
	->filter(function ($content) {
		return lotsOfRegexpContentFiltering($content);
	})
	->reduce(function ($accumulator, $content) {
		return $accumulator.retrievePartsToCollect($content);
	}, '');

As a generator can be traversed only once, the result can be persisted in a classic Collection to be used as data source for multiples transformations :

/** @var Collection $reusableCollection */
$reusableCollection = $generatorCollection->persist();

Functional helpers

This package provides functional helpers to use collection pipelines focused on operations :

use function Pitchart\Collection\Helpers\map;

map([1, 2, 3, 4], function ($item) {
    return $item + 1;
})
->filter(function ($item) {
    return $item % 2 == 0;
});

You can also use them to perform operations on any iterable datas, IE arrays or traversable objects, with a consistent API.

Test

make test

License

The MIT License (MIT). Please see License File for more information.