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Date: Wed, 8 Aug 2012 22:49:59 -0400
Message-ID: <CAL+t6cFRp20Emi-fRqLter8hjPKcQowZTvK0jb9yL2gowQ63bg@mail.gmail.com>
To: Larry Garfield <larry@garfieldtech.com>
Cc: internals@lists.php.net
Content-Type: text/plain; charset=ISO-8859-1
Subject: Re: [PHP-DEV] Re: Generators in PHP
From: theanomaly.is@gmail.com (Sherif Ramadan)

>
> 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.