A deprecation warning on is_callable() would imply that in a future
version of PHP that call will be illegal.
But this is not the case.
is_callable() is meant to accept any value, and return true or false.
is_callable('static::method') will still be a valid call in future
versions, only the result will be different.
This change simply cannot be covered with a deprecation warning.
Developers have to update their code when they upgrade to PHP 9.x, or
they need a PHP_VERSION_ID check, as sad as that is.One solution could be to accept an additional parameter to enable the forward behavior for is_callable(). But then this parameter would have to be removed again later. Also, is_callable() already has two extra parameters, so it would get crowded. -- Andreas On Tue, 19 Apr 2022 at 17:18, Claude Pache <claude.pa...@gmail.com> wrote: > > > > > Le 18 mars 2022 à 18:03, Juliette Reinders Folmer > > <php-internals_nos...@adviesenzo.nl> a écrit : > > > > On 18-3-2022 14:37, Christoph M. Becker wrote: > >> On 16.03.2022 at 06:52, Juliette Reinders Folmer wrote: > >>> I've just been looking in detail at the Partially Supported Callables > >>> deprecation RFC: > >>> https://wiki.php.net/rfc/deprecate_partially_supported_callables > >>> The RFC explicitly excludes the `is_callable()` function and the > >>> `callable` type from throwing deprecation notices. > >>>> The |is_callable()| function and |callable| type remain side-effect > >>>> free and do not throw a deprecation warning. They will continue to > >>>> accept these callables until support is removed entirely. > >>> While I can fully support this for the `callable` type, I wonder if the > >>> decision to not throw a deprecation on use in `is_callable()` is the > >>> right one (though I understand the desire to keep it side-effect free). > >>> Consider these code samples: > >>> function foo(callable $callback) {} > >>> foo('static::method'); > >>> This function call not throwing a deprecation is not problematic as in > >>> PHP 9.0 the function will start throwing a TypeError. > >>> if (is_callable('static::method')) { > >>> static::method(); > >>> } > >>> The second code sample, however, is problematic, as in PHP 9.0, the > >>> behaviour of this code will be silently reversed for those callbacks > >>> which would previously result in `is_callable()` returning true, which > >>> makes this a potentially dangerous change without deprecation notice. > >>> Would anyone care to enlighten me as to whether this was given due > >>> consideration ? > >> Frankly, I don't know. Apparently, there was almost no discussion about > >> that RFC. Part of the reasoning to not raise E_DEPRECATED when calling > >> is_callable() was likely the typical use case > >> $callable = …; > >> if (is_callable($callable)) { > >> call_user_func($callable); > >> } > >> what would report the deprecation when actually calling the callable. > >> Not sure what to do regarding your given use case(s). > >> -- > >> Christoph M. Becker > > > > Unfortunately, those aren't the only places I see this happening and my > > example is not a stand-alone case either. > > > > I came across the above code sample ( is_callable('static::method') / > > is_callable(['parent', __FUNCTION__]) with variable method calls) in a > > number of different packages when testing a (PHPCompatibility) sniff I am > > writing to detect the deprecation, so this code pattern looks to be > > relatively common. > > > > Some examples: > > * > > https://github.com/symfony/service-contracts/blob/bc0a2247c72d29241b5a06fb60dc1c9d9acf2a3a/ServiceSubscriberTrait.php#L39 > > * > > https://github.com/mockery/mockery/blob/c10a5f6e06fc2470ab1822fa13fa2a7380f8fbac/library/Mockery/Mock.php#L960 > > * > > https://github.com/simplepie/simplepie/blob/dacf0ed495d2e8fb306e526ca3f2a846af78a7c9/tests/oldtests/absolutize/RFC3986.5.4/base.php#L13 > > > > As I think that it is a serious oversight of the RFC, I have open: > > https://github.com/php/php-src/issues/8401 > <https://github.com/php/php-src/issues/8401> > > —Claude > > -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: https://www.php.net/unsub.php
