kuria/iterable

Utilities for dealing with PHP's iterators and the iterable type

v1.0.1 2022-02-05 13:52 UTC

This package is auto-updated.

Last update: 2024-11-22 18:06:01 UTC


README

Utilities for dealing with PHP's iterators and the iterable type.

https://travis-ci.com/kuria/iterable.svg?branch=master

Contents

Features

  • converting iterable values to arrays
  • caching iterator

Requirements

  • PHP 7.1+

Usage

IterableHelper::toArray()

Convert an iterable value to an array.

<?php

use Kuria\Iterable\IterableHelper;

$array = IterableHelper::toArray($iterable);
  • if the value is already an array, it is returned unchanged
  • if an iterator yields multiple values with the same key, only the last value will be present in the array

IterableHelper::toList()

Convert an iterable value to an array with consecutive integer indexes.

<?php

use Kuria\Iterable\IterableHelper;

$list = IterableHelper::toList($iterable);
  • if the value is already an array, only its values will be returned (keys are discarded)
  • if the value is traversable, all its values will be returned

CachingIterator

CachingIterator can be used to wrap any \Traversable instance so it can rewinded, counted and iterated multiple times.

  • as the traversable is iterated, its key-value pairs are cached in memory
  • the cached key-value pairs are reused for future iterations
  • when the traversable is fully iterated, the internal reference to it is dropped (since it is no longer needed)

This is mostly useful with generators or other non-rewindable traversables.

<?php

use Kuria\Iterable\Iterator\CachingIterator;

function generator()
{
    yield random_int(0, 99);
    yield random_int(100, 199);
    yield random_int(200, 299);
}

$cachingIterator = new CachingIterator(generator());

print_r(iterator_to_array($cachingIterator));
print_r(iterator_to_array($cachingIterator));
var_dump(count($cachingIterator));

Output:

Array
(
    [0] => 29
    [1] => 107
    [2] => 249
)
Array
(
    [0] => 29
    [1] => 107
    [2] => 249
)
int(3)

Note

Your numbers will vary, but the output is meant to demonstrate that the yielded pairs have indeed been cached.