.. _php-yieldusage:

.. _yield-usage:

Yield Usage
+++++++++++

  Usage of generators, with yield keyword.

Yield was introduced in PHP 5.5, and is backward incompatible.

.. code-block:: php
   
   <?php
   
   function prime() {
       $primes = [2, 3, 5, 7, 11, 13, 17, 19];
       foreach($primes as $prime) {
           yield $prime;
       }
   }
   
   ?>

See also `Generator Syntax <https://www.php.net/manual/en/language.generators.syntax.php>`_, `Deal with Memory Gently using "Yield" in PHP <https://medium.com/tech-tajawal/use-memory-gently-with-yield-in-php-7e62e2480b8d>`_ and `Understanding PHP Generators <https://scotch.io/tutorials/understanding-php-generators>`_.

Connex PHP features
-------------------

  + `yield <https://php-dictionary.readthedocs.io/en/latest/dictionary/yield.ini.html>`_
  + `yield-from <https://php-dictionary.readthedocs.io/en/latest/dictionary/yield-from.ini.html>`_


Specs
_____

+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Short name   | Php/YieldUsage                                                                                                                                                                          |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Rulesets     | :ref:`All <ruleset-All>`, :ref:`Appinfo <ruleset-Appinfo>`, :ref:`CE <ruleset-CE>`, :ref:`Changed Behavior <ruleset-Changed-Behavior>`                                                  |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Exakat since | 0.8.4                                                                                                                                                                                   |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| PHP Version  | With PHP 5.5 and more recent                                                                                                                                                            |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Severity     |                                                                                                                                                                                         |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Time To Fix  |                                                                                                                                                                                         |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Precision    | Very high                                                                                                                                                                               |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+
| Available in | `Entreprise Edition <https://www.exakat.io/entreprise-edition>`_, `Community Edition <https://www.exakat.io/community-edition>`_, `Exakat Cloud <https://www.exakat.io/exakat-cloud/>`_ |
+--------------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+