On 12/09/2015 07:35 PM, yary wrote:
This feature builds upon the generator functionality introduced into
PHP 5.5. It enables for a return statement to be used within a
generator to enable for a final expression to be returned (return by
reference is not allowed). This value can be fetched using the new
Generator::getReturn() method, which may only be used once the
generator has finishing yielding values.
<?php
$gen = (function() {
yield 1;
yield 2;
return 3;
})();
foreach ($gen as $val) {
echo $val, PHP_EOL;
}
echo $gen->getReturn(), PHP_EOL;
The above example will output:
1
2
3
Being able to explicitly return a final value from a generator is a
handy ability to have. This is because it enables for a final value to
be returned by a generator (from perhaps some form of coroutine
computation) that can be specifically handled by the client code
executing the generator. This is far simpler than forcing the client
code to firstly check whether the final value has been yielded, and
then if so, to handle that value specifically.
So this is meant as some sort of "EOF" (or rather EOL) marker, right?
Perl 6 does not do this, because there's already an EOF mechanism, and
you can use LAST phasers to execute after the final iteration, but still
inside the scope of the loop that works with the list.
Cheers,
Moritz
