The missing PHP iterators.
CachingIteratorAggregateClosureIterator:ClosureIterator(callable $callable, array $arguments = [])ClosureIteratorAggregate:ClosureIteratorAggregate(callable $callable, array $arguments = [])IterableIterator:IterableIterator(iterable $iterable)IterableIteratorAggregate:IterableIteratorAggregate(iterable $iterable)PackIterableAggregateUnpackIterableAggregatePausableIteratorAggregateRandomIteratorAggregate
composer require loophp/iterators
Let you cache any iterator. You then get \Generators rewindable for free.
This implementation does not use internal state to keep track of the current position of the iterator. The underlying mechanism is based on SPL \CachingIterator.
The pros of using that iterator is performance. It's blazing fast, it cannot compare to any other stateful custom implementations.
This iterator will cache keys and values, of any type.
<?php
// Generator
$generator = static function (): \Generator {
yield true => 'foo';
yield false => 'bar';
yield ['foo', 'bar'] => 'foobar';
};
$iterator = new CachingIteratorAggregate($generator());
foreach ($iterator as $key => $value); // This will work.
foreach ($iterator as $key => $value); // This will also work.<?php
// Generator
$generator = static function (): \Generator {
yield true => 'foo';
yield false => 'bar';
yield ['foo', 'bar'] => 'foobar';
};
$iterator = new PackIterableAggregate($generator());
foreach ($iterator as $value);
/*
$value will yield the following values:
- [true, 'foo']
- [false, 'bar']
- [['foo', 'bar'], 'foobar']
*/<?php
// Generator
$generator = static function (): \Generator {
yield [true, 'foo'];
yield [false, 'bar'];
yield [['foo', 'bar'], 'foobar'];
};
$iterator = new UnpackIterableAggregate($generator());
foreach ($iterator as $key => $value);
/*
$key and $value will yield the following values:
- true => 'foo'
- false => 'bar'
- ['foo', 'bar'] => 'foobar'
*/<?php
$callable = static fn (int $from, int $to) => yield from range($from, $to);
$iterator = new ClosureIterator($callable(10, 20));<?php
$iterator = new IterableIterator(range(1, 10));<?php
$inputIterator = new ArrayIterator(range('a', 'e'));
$iteratorAggregate = new PausableIteratorAggregate($inputIterator);
$i = 0;
foreach ($iteratorAggregate as $v) {
var_dump($v) // Print: 'a', 'b', 'c'
if (++$i === 2) {
break;
}
}
foreach ($iteratorAggregate->rest() as $v) {
var_dump($v) // Print: 'd', 'e'
}In order to properly use this iterator, the user need to
provide an extra parameter seed. By default, this parameter
is set to zero and thus, the resulting iterator will be
identical to the original one.
Random items are selected by choosing a random integer between
zero and the value of seed. If that value is zero, then the
iterator will yield else it will skip the value and start
again with the next one.
The bigger the seed is, the bigger the entropy will be and
the longer it will take to yield random items.
It's then up to the user to choose an appropriate value.
Usually a good value is twice the approximate amount of items
the decorated iterator has.
If you're willing to iterate multiple times on this, use the
CachingIteratorAggregate to cache the results.
This iterator works on keys and values, of any type.
<?php
$seed = random_int(0, 1000);
$inputIterator = new ArrayIterator(range('a', 'e'));
$iterator = new RandomIterableAggregate($inputIterator, $seed);
foreach ($iterator as $v) {
var_dump($v);
}
$iterator = new CachingIteratorAggregate(
(new RandomIterableAggregate($inputIterator, $seed))->getIterator()
);
foreach ($iterator as $v) {
var_dump($v);
}
foreach ($iterator as $v) {
var_dump($v);
}Every time changes are introduced into the library, Github runs the tests.
The library has tests written with PHPUnit.
Feel free to check them out in the tests directory.
Before each commit, some inspections are executed with GrumPHP; run
composer grumphp to check manually.
The quality of the tests is tested with Infection a PHP Mutation testing
framework - run composer infection to try it.
Static analyzers are also controlling the code. PHPStan and PSalm are enabled to their maximum level.
Feel free to contribute by sending Github pull requests. I'm quite responsive :-)
If you can't contribute to the code, you can also sponsor me on Github.
See CHANGELOG.md for a changelog based on git commits.
For more detailed changelogs, please check the release changelogs.