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Date: Wed, 19 Mar 2025 17:10:21 +0000
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Subject: Re: [PHP-DEV] PHP True Async RFC - Stage 2
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From: imsop.php@rwec.co.uk ("Rowan Tommins [IMSoP]")



On 19 March 2025 15:51:38 GMT, Edmond Dantes <edmond=2Eht@gmail=2Ecom> wro=
te:
>>
>>  "Cheating" in the sense that you wrote out a "general syntax",
>>
>I got it=2E
>
>> That's not the problem; the problem is that the following are all
>equivalent expressions:
>>  (((foo())))
>
>In principle, this is not a problem because the expression in parentheses
>preceded by `spawn` is unambiguously a call expression=2E
>That is, from an analysis perspective, everything is fine here because th=
e
>expression `spawn ()` is a syntax error=2E


This has nothing to do with my examples=2E

If you start with a valid expression, you can add any number of parenthese=
s around it, and get another valid expression, with the same meaning=2E A f=
unction call is an expression, and a function call wrapped in parentheses i=
s another way of writing the same expression=2E

But even though we're talking in circles about why, your latest examples d=
o avoid the particular problem I was trying to describe=2E



>From the user's perspective, what is the difference between these two
>expressions?
>
>```php
>spawn function(): string { =2E=2E=2E };
>spawn (function(): string { =2E=2E=2E });
>```


Yes, that would probably be a bad choice as well=2E Which is why I've repe=
atedly suggested a different keyword, and AFAIK you still haven't actually =
voiced an opinion on that=2E


>If we define the rule `spawn function_call`, then `spawn` acts as a prefi=
x
>in this expression=2E However, everything that is already defined for
>`function_call` in PHP must remain valid=2E


Yep, I'm totally fine with that=2E But you kept referring to that token as=
 "expression", which confused me, because that's a different thing in the g=
rammar=2E



>The second form of the `spawn` expression is:
>```php
>spawn inline_function
>```


This part totally makes sense from a syntax point of view, I just think it=
 has bad usability - the user has to type a bunch more boilerplate, which l=
ooks like something it's not=2E



>>  If it's going to be a special case for an "inline coroutine", just use=
 a
>keyword other than "function", so it doesn't look like an expression when
>it's not, like "spawn block { =2E=2E=2E }"; or no keyword at all, just "s=
pawn {
>=2E=2E=2E }"
>>
>
>Well, yes, but here we again face the issue with `returnType` syntax, whi=
ch
>ends up hanging in the air=2E=2E=2E


I think I asked this before: why would anyone want to specify a return typ=
e there?=20

I assumed the actual user scenario we're trying to solve is "I have a bunc=
h of statements I want to run in a new Coroutine, but they're not worth put=
ting in a function"=2E So to the user, having all the features of a functio=
n isn't relevant=2E We don't allow specifying the return type of a match st=
atement, for example=2E

Do you have a different scenario in mind?


Rowan Tommins
[IMSoP]