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Subject: Re: [PHP-DEV] RFC - Array Of for PHP 7
From: rowan.collins@gmail.com (Rowan Collins)

On 25 October 2017 22:52:37 BST, Dan Ackroyd <danack@basereality=2Ecom> wro=
te:
>Although 'array of' as well as full blown generics are popular ideas,
>I'm pretty certain the RFC failed due to the type check on the array
>happening every time the 'array of' was passed from one function to
>another, which would make it too slow to actually use=2E

The fundamental problem with extending PHP's type declarations - either to=
 more complex types, or to other code elements such as properties - is that=
 they are currently always checked at run-time, not with a separate static =
analyser=2E It's notable that in Go, the runtime type checks are considered=
 a "development only" option, and strongly discouraged in production code d=
ue to performance impact=2E

I wrote about this a few months back here: http://rwec=2Eco=2Euk/q/php-typ=
e-system

One possibility if we do want to keep the current run-time approach is to =
cache type information against values (zvals) so subsequent checks become q=
uicker=2E The problem is working out exactly what to store and when to inva=
lidate it - if you append 42 to an array that passed int[] on the last chec=
k, the ideal would be for us to know the type is still valid=2E

Regards,

--=20
Rowan Collins
[IMSoP]