On Thu, Mar 25, 2021 at 1:14 PM Mike Schinkel <m...@newclarity.net> wrote:
> > On Mar 25, 2021, at 12:50 PM, Rowan Tommins <rowan.coll...@gmail.com>
> wrote:
> >
> > On 25/03/2021 15:02, Mike Schinkel wrote:
> >> Can you please clarify why "function(...) use(...) {...}" can't be
> their solution when someone needs by-reference capture?
> >
> >
> > For the same reason - or lack of reason - why it can't be the solution
> when they need by-value capture. In other words, whatever reason people
> have for wanting this RFC.
>
> Are you proposing auto-capture but one that is note able to change the
> variable's value in the outer scope?
>
> Since code is worth 1000 words, here is an example of what I think you are
> saying:
>
> $x = 1;
> example(fn() {
> echo $x; // This would print "1"
> $x = 2;
> echo $x; // This would print "2"
> });
> echo $x; // This would still print "1"
>
> If that is what you are saying — which I did not get from your prior
> arguments — then I myself would be fine with "by-value" capture.
>
> What I like about the RFC is being able to omit the use(...) when
> referencing (reading) a variable inside the closure that come from the
> outer scope. But almost all of my use-cases would work fine with by-value
> semantics, and for the rest I could use "function(...)use(...){...}."
>
> That said, I again suggest this we could omit the "use" keyword for short
> functions:
>
> // 2nd set of parens acts as an implied "use":
> example( fn()(&$var) => $var = value() );
>
>
That wouldn't work though if example expects a callback with a defined
signature. "Use function() use()" in that case might be a valid solution,
but just wanted to throw it out there. Silly example:
$counter = 0;
array_map(fn($a) => {$counter++; return $a+1},$array);
If you tried to pass in $counter as a parameter, it would fail.
> -Mike
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--
Chase Peeler
chasepee...@gmail.com
