On Thu, Aug 9, 2012 at 4:49 AM, Sherif Ramadan <theanomaly...@gmail.com> wrote:
>>
>> One question, though: It looks based on the voting like finally {} blocks
>> are going in. So... what should happen in the following situation:
>>
>> function stuff() {
>> try {
>> foreach (range(1, 100) as $i) {
>> yield $i;
>> }
>> }
>> finally {
>> print "All done";
>> }
>> }
>>
>> Does "All done" get printed once, or 101 times? Similarly:
>>
>> function things() {
>> $i = 1;
>> try {
>> while (true) {
>> yield $i++;
>> }
>> }
>> finally {
>> print "All done";
>> }
>> }
>>
>> That will run indefinitely. So will "All done" ever print, or does that
>> finally become unreachable?
>>
>> (I have no clue what the behavior "should" be in these cases, just that it
>> should be sorted out sooner rather than later.)
>>
>
>
> Based on my understanding of both RFCs, I don't see that this would be
> a conflict or lead to unexpected behavior. As stated by the generators
> RFC: "When you first call the generator function ($lines =
> getLinesFromFile($fileName)) the passed argument is bound, but nothing
> of the code is actually executed. Instead the function directly
> returns a Generator object.".
>
> So in the event we are calling the function stuff(), nothing should
> actually be executed, and as we iterate over the traversable object
> the generator should be "passing control back and forth between the
> generator and the calling code". This would be indicated by the
> "yield" keyword present in the function. Meaning you should see the
> expected result and finally should only ever be called once in your
> first example.
>
> As for you second example... Obviously if you've created an infinite
> loop you've made everything outside of the loop unreachable, whether
> you're using generators or not.
>
> However, I'll let the author of the RFC provide any clarification or
> corrections where I might be wrong.
Yes, that is basically right. The one interesting case that arises
when using generators is what happens when you close a generator
before it is finished. E.g. in the function mentioned above:
function stuff() {
try {
foreach (range(1, 100) as $i) {
yield $i;
}
} finally {
print "All done";
}
}
--
PHP Internals - PHP Runtime Development Mailing List
To unsubscribe, visit: http://www.php.net/unsub.php
