>
> On Jan 21, 2020 at 5:37 PM, <Rowan Tommins (mailto:rowan.coll...@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.
>
>
>
>
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>
Those are all really good points.
Unfortunately. :-(
-Mike
