Iterable

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

Contents

• Features
• Requirements
• Usage
  • IterableHelper::toArray()
  • IterableHelper::toList()
  • CachingIterator

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.