wmde / traversable-iterator
Turn Traversable objects into Iterators. Fixed version of the native IteratorIterator
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Requires
- php: >=7.0
Requires (Dev)
- mediawiki/mediawiki-codesniffer: ~0.8.0
- ockcyp/covers-validator: ~0.6
- phpunit/phpunit: ~6.2
- squizlabs/php_codesniffer: ~2.9
This package is not auto-updated.
Last update: 2024-10-27 05:36:05 UTC
README
Iterator
that can be constructed from Traversable
objects.
Can be seen as a fixed version of IteratorIterator
(which is used internally). IteratorIterator
behaves in unexpected ways when constructed from an IteratorAggregate
: it only calls getIterator
once rather than once per iteration, which is what happens when you traverse the IteratorAggregate
directly. In other words: looping over an IteratorIterator
that contains a IteratorAggregate
yields
different behaviour than looping over the IteratorAggregate
itself. This is unexpected and can be
problematic. For instance when the IteratorAggregate
contains a Generator
(which happens often),
looping over the IteratorIterator
more than once will cause an error due to the Generator
not
being rewindable.
Example of how IteratorIterator
fails:
$iteratorAggregate = new class() implements \IteratorAggregate { public function getIterator() { yield 'a'; yield 'b'; yield 'c'; } } $iterator = new IteratorIterator( $iteratorAggregate ); foreach ( $iterator as $value ) {} foreach ( $iterator as $value ) {} // Exception: Cannot rewind a generator that was already run
This exception, and more generally difference in behaviour, does not occur when using TraversableIterator
.
Installation
To add this package as a local, per-project dependency to your project, simply add a
dependency on wmde/traversable-iterator
to your project's composer.json
file.
Here is a minimal example of a composer.json
file that just defines a dependency on
Traversable Iterator 1.x:
{ "require": { "wmde/traversable-iterator": "~1.0" } }
Usage
Running the tests
For a full CI run
composer ci
For tests only
composer test
For style checks only
composer cs
Release notes
1.0.0 (2017-06-17)
- Initial release