> > > On Sun, Apr 25, 2021, at 2:25 PM, Larry Garfield wrote: > > > > Greetings, Internalians! > > > > > > > > I would like to offer for your consideration another RFC, > specifically > > > > syntax for partial function application. > > > > > > > > https://wiki.php.net/rfc/partial_function_application > > > > > > > > It includes an implementation by Joe Watkins that is already about > 95% > > > > complete. (There's some edge cases he's still sorting out, but all > of > > > > the typical cases should work already.) Most of the design work > comes > > > > from Levi Morrison and Paul Crovella. I helped out with the tests, a > > > > few edge bits, and general instigator/nudge. :-) > > > > > > > > Discuss. > > > > > > It looks like the conversation has died down, and it's been two weeks, > so > > > pending any other notable feedback I'll open a vote on this RFC on > Thursday > > > or Friday. > > > > > > --Larry Garfield > > > > > > > LGTM, thanks for the RFC! > > > > What about visibility? I suppose this works even outside the object > scope? > > should this be mentionned? > > $foo = $this->somePrivateMethod(1, ?) > > We're pretty sure it will work, and if you return $foo to another caller > and then call it, it will work fine. We'll add a test to confirm that. > > > Would it make sense to support a way to use a placeholder for "all > > remaining args"? > > Eg: > > $foo = some_func(1, ...?) > > That's already implicit in the way it works now. If you placeholder at > least one parameter, and then don't fill in all of the remaining > parameters, any additional trailing parameters are always placeholdered. > So $obj->foo(?) will always return a partial that has the same arity as > foo() does, regardless of how many parameters it has. > > > Combined with my previous comment, this could replace > > Closure::fromCallable() by a language construct, which is something that > we > > already discussed in another thread (we talked about some ::function > > special suffix instead): > > $foo = $this->somePrivateMethod(...?) > > Yep. That's noted in the RFC. Although not the primary intent, a nice > side effect is that any_func(?) is now a safe way to turn any > function/method into a callable to reference it. That renders ::function > or similar 98% unnecessary. (The remaining cases are mostly where you need > to collect data statically for compilation or similar.) >
Great news! > In this last form, we might make this result in Closure::fromCallable() > > exactly. Aka no increase of the depth of the stack trace. > > > > BTW, ideally, partial functions should not increase the depth of the > > stacktrace at all. Do they? > > > > Nicolas > > They currently do, since they work by creating a Closure-esque object > called Partial with an __invoke() method. However, if you partial the same > thing multiple times then only one stack level gets added. > Nice. Would it be possible to optimize this and remove the extra frame? At least maybe for the (?) case? This makes me wonder: can we create a partial programmatically? Wouldn't that be needed for some use cases? Partial::createFromCallable($callable, the-args)? Nicolas
