Re: [RFC][DISCUSSION] Collection Inspection

> > On Thu, Jan 25, 2018 at 2:39 PM, Niklas Keller <me@kelunik.com> wrote: > >> >> So, given $a collectionof string the operator returns >> whether or not $a >>> is, at that time, a collection of strings (be it an array or other >>> iterable). It doesn't insure $a will stay that way - it's just a check of >>> the variables status at a given moment, which is the best that can be >>> hoped >>> for in PHP. >>> >> >> That should be a function, not an operator, unless you can bring up very >> good arguments to make it an operator. >> > > Consistency with instanceof. > > > > Hmm, it might be possible to just pile this all onto instanceof - > following Derrick's mention of how Java does things, so here's a third > implementation approach. It would look like this: > > $a instanceof array<string> > That might work, but array<string> should only return true if it's an array, not for anything that implements ArrayAccess. > Returns true if $a is an array (or implements array access) and that all > it's members are strings. > > $b instanceof SomeClass<string> > > Returns true if SomeClass can be iterated and contains only strings. > This would block generics with that syntax then. > The question is can the token parser handle that pattern? Or does the > current usage of < and > in their boolean form block this? > > If this third approach is accepted then we have no BC breaks at all since > there's no new keyword or function. We just have a *very* expanded > instanceof operator. > Regards, Niklas