Re: [RFC][Discuss] Arrow Functions

Hi Stephen, > On Feb 3, 2017, at 10:38 PM, Stephen Reay <php-lists@koalephant.com> wrote: > > >> >> I absolutely agree that it's terrible… the point is that types (even potential >> future union types) can be used with short closures, but it certainly doesn't mean they should >> be. I don't think confusion with a non-existent and non-recommended way of coding should be a >> reason against a particular syntax. > > Using type hints is a part of the language. It even has benefits that I can absolutely see > being used here: > > array_map(function(Foo $x) => $x->bar()); > > If Foo is a class/interface with a method of bar, your IDE can know that it's a valid > method to call. > > That of course is in addition to the benefit of getting useful type errors from PHP itself. You raise a good point about IDEs, types might have a place with short closures. Still, I don't see union types, if they ever exist, being common here. Taking your example with the other proposed syntax: array_map(|Foo $x| => $x->bar()); Honestly I'm not sure which is better… personal preference at this point, each has their merits. >> >>> As has been said before, PHP is relatively verbose compared to other languages. That >>> makes it slightly more characters to type, but it also makes it absolutely clear what is happening. >> >> Using function IMO makes it more likely to confuse a short >> closure with a regular closure. Reusing the function keyword with >> different semantics may result in some confusion. >> > > So we should instead use syntax already used for bit wise OR, and further confuse the situation > when the function has no parameters and reusing the logical OR operator. Brilliant. This is certainly a downside, though expressions cannot start with a logical or bitwise OR, so that will help differentiate them. However, it is hard to argue that function could be confusing when something like || => $x ** 2 may be more confusing, so point taken. Regardless, I still prefer the visual difference since the auto-capture behavior is so different from other functions. Cheers! Aaron Piotrowski