On Tue, Mar 14, 2023 at 1:57 PM Rowan Tommins <rowan.coll...@gmail.com> wrote: > > On Tue, 14 Mar 2023 at 10:39, Bob Weinand <bobw...@hotmail.com> wrote: > > > Hey Rowan, > > > > do we actually need *positional* partial application, after a ... token? > > > > Would it not be enough, to simply forbid positional arguments after a ... > > and just allow named arguments? These already have well defined position > > independent semantics. > > > > There may be some desire for a single argument placeholder later on, but > > this can be introduced later, separately. > > > > > Yes, named parameters would certainly be better than left-to-right only. > It's definitely less elegant, though, and given that PFA is largely > short-hand for a short closure anyway, I think conciseness is quite an > important aim. > > To take a couple of the above examples, and compare existing short closure, > fully positional PFA, and named-after-placeholder PFA: > > $isLogger = fn($object) => is_subclass_of($object, LoggerInterface::class, > false); > $isLogger = is_subclass_of(?, LoggerInterface::class, false); > $isLogger = is_subclass_of(..., class: LoggerInterface::class, > allow_string: false); > > $priceFormatter = fn(float $num) => number_format($num, 2, ',', '.'); > $priceFormatter = number_format(?, 2, ',', '.'); > $priceFormatter = number_format(..., decimals: 2, decimal_separator: ',', > thousands_separator: '.'); > > Arguably the named param version is more explicit, but in some cases it's > significantly longer than manually defining a closure, whereas fully > positional PFA is always shorter. > > Regards, > -- > Rowan Tommins > [IMSoP]
Something I was partial to (pun slightly intended), when thinking about it last summer was to put named parameters with dots following, like this: $isLogger = is_subclass_of(object_or_class..., LoggerInterface::class, false); // or, since this is a beginning/end partial, this is the same: $isLogger = is_subclass_of(..., LoggerInterface::class, false); $isLogger(object_or_class: $myClass); // or $isLogger($myClass); $priceFormatter = number_format(num..., 2, ',', '.'); At least, that was what I was going to propose, according to my notes. Looking at it 8 months later, I still kinda like it. -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
