Comparison of generator with foreach and yield from

generatorForEach.php

<?php declare(strict_types=1);

class Test
{
        private $arr = [];

        public function __construct()
        {
                for ( $i = 0; $i < 10000; $i++ )
                {
                        $this->arr["key{$i}"] = "value{$i}";
                }
        }

        public function getIterator() : Iterator
        {
                foreach ( $this->arr as $key => $value )
                {
                        yield $key => $value;
                }
        }
}

$test = new Test();

foreach ( $test->getIterator() as $key => $value )
{
        echo $key, ' => ', $value, "\n";
}

generatorYieldFrom.php

<?php declare(strict_types=1);

class Test
{
        private $arr = [];

        public function __construct()
        {
                for ( $i = 0; $i < 10000; $i++ )
                {
                        $this->arr["key{$i}"] = "value{$i}";
                }
        }

        public function getIterator() : Iterator
        {
                yield from $this->arr;
        }
}

$test = new Test();

foreach ( $test->getIterator() as $key => $value )
{
        echo $key, ' => ', $value, "\n";
}

A blackfire performance comparison with 100 samples for each script can be found here: https://blackfire.io/profiles/compare/cef5b2d8-a511-443b-bad7-8a49a9918258/graph

When looking at the comparison of the vld OPCode output of both scripts, it gets clear where the better performance for yield from comes from.