1.2.709. Misused Yield

When chaining generator <https://www.php.net/`generator>`_, one must use the yield from keyword.

Forgetting the yield from keyword cancels the generator <https://www.php.net/`generator>`_ nature of the functioncall and nothing is emited.

Using yield on a generator <https://www.php.net/`generator>`_, yields … the generator <https://www.php.net/`generator>`_, not the values of the generator <https://www.php.net/`generator>`_.

It is legit to yield a generator <https://www.php.net/`generator>`_, for later usage. This is just very uncommon, and worth a check.

<?php

function foo() {
     yield 1;
     // Goo is called, but not run as a generator
     goo();
}

function hoo() {
     yield 1;
     // Goo is yield, but not run as a generator
     yield goo();
}

function goo() {
     yield 3;
}

?>

1.2.709.1. Suggestions

• Use the yield from keyword

1.2.709.2. Specs

Short name	Structures/MisusedYield
Rulesets	All, Analyze, Changed Behavior
Exakat since	2.5.2
PHP Version	All
Severity	Minor
Time To Fix	Quick (30 mins)
Precision	Very high
Features	yield-from
Available in	Entreprise Edition, Exakat Cloud