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Subject: Re: [PHP-DEV] add Fiber (sackful coroutine) support
From: rowan.collins@gmail.com (Rowan Collins)

On 31 August 2017 15:28:36 BST, Haitao Lv <i@lvht=2Enet> wrote:
>So I propose to introduce the sackful coroutine, aka Fiber, support for
>PHP=2E

Hi!

Is this your own invention, or is the name and semantics based on some exi=
sting language or computer science theory? "Fiber" makes me think of string=
s, rather than coroutines, so maybe I'm missing a key metaphor here=2E


>> <?php
>> function foo($a)
>> {
>>   $b =3D await $a + 1;
>>   echo $b;
>> }

Should "await" be "yield" here? If not, what happens if I call foo() witho=
ut being inside a Fiber?

Similarly, if I run bar() and it runs foo(), what result will I get outsid=
e a Fiber, since bar() has no yield, so is not itself a generator?


>So the Fiber API is a little like the Generator API, but is more simple
>yet powerful=2E So there
>is no need to distinct $generator->current(), $generator->send(), and
>$generator->getReturn()=2E

I don't really follow how merging the current() and send() methods is rela=
ted to whether the coroutine was paused further into the stack=2E Your ->re=
sume() doesn't seem to do anything a normal generator can't, except that th=
e yield is nested deeper=2E Nor does it seem to replace getReturn() (althou=
gh I struggled to understand the rationale for that addition at the time, o=
thers swore it was necessary)=2E

Meanwhile, how does this relate to other ways of combining generators, suc=
h as "yield from"?

I do struggle with coroutines, so I may be missing something obvious here=
=2E

Regards,

--=20
Rowan Collins
[IMSoP]