Re: Typed array properties V2

> > On Jan 21, 2020 at 5:37 PM, <Rowan Tommins (mailto:rowan.collins@gmail.com)> wrote: > > > > On 20/01/2020 00:53, Mike Schinkel wrote: > > One approach mentioned by Andrea Faulds was to extend the hashtable (ref: your > > article[1]) and count types as assigned just like we currently count references. So a 10,240 element > > array of ints could have an internal tracker showing that the array contains type(s): > > ['int' => 10240]. Append a string value to the array and then the types would be > > ['int' => 10240, 'string' => 1]. > > > This would work really well for simple types like 'int' and 'string', > but loses its advantage fast with things like interfaces and > pseudo-types. For instance, if you have an array with objects of 20 > different classes, and need to check it against a constraint of > SomeInterface[], you still have to test all 20 classes to see if they > implement that interface. > > The overhead is also rather high, because you have to allocate memory > for this list on every array, and keep it up to date on every write, > even if it's never used. > > I've had a similar idea in the past, but rather than trying to list the > types in advance, just cache them after passing (or failing) a type > check, so more like [ 'SomeInterface[]' => true, 'SomeOtherInterface[]' > > => false ]. Even if you just wiped the cache completely on every write, > I think that would give a decent boost, because there will often be > cases where a value is passed through a series of related functions all > expecting the same type. > > The worst case pseudotype is probably "callable[]", because it's > actually context-dependent (e.g. [$object, 'privateMethod] is only > "callable" inside the same class as $object) so can't be pre-calculated > or cached. That would be problematic even with full generics - > logically, List<callable> would check each member was callable when it > was added to the list, but it might turn out not to be callable when it > was accessed later. > > > > > > > > > Those are all really good points. Unfortunately. :-( -Mike