Generator with subgenerator

yield-from.php

<?php
$generatorWithTwoWayCommunication = function()
{
    $randomValue = mt_rand();
    yield $randomValue;
    $receivedFromOuterSpace = yield;
    $returnValue = yield from subGenerator($receivedFromOuterSpace, $randomValue);
    return $returnValue;
};

function subGenerator($valueFromOuterSpace, $randomValue)
{
    yield $valueFromOuterSpace * $valueFromOuterSpace;
    yield $valueFromOuterSpace * $randomValue;
    return 'Lis Witalis';
};

$generator = $generatorWithTwoWayCommunication();
$valueFromFirstIteration = $generator->current();
$generator->next();
$valueFromSecondIteration = $generator->send(666);
$generator->next();
$valueFromThirdIteration = $generator->current();
$generator->next();
$valueReturnedFromGenerator = $generator->getReturn();