Re: Strict typing and callback vs declare()

On Thu, Feb 26, 2015 at 11:56 AM, Dmitry Stogov <dmitry@zend.com> wrote: > > > On Thu, Feb 26, 2015 at 1:34 PM, Benjamin Eberlei <kontakt@beberlei.de> > wrote: > >> >> >> On Thu, Feb 26, 2015 at 11:10 AM, Dmitry Stogov <dmitry@zend.com> wrote: >> >>> Hi Anthony, >>> >>> What do you think about using a user level callback for strict type >>> checks >>> instead of declare(). It won't allow changing behavior per file, but this >>> has its own cons and pros. >>> >>> <?php >>> set_strict_type_checker(function ($class_name, $function_nume, $arg_num, >>> $expected_type, $value, $file, $line) { >>> ... >>> return false; >>> }); >>> include("orig_index.php"); >>> ?> >>> >>> If callback is not set, arguments are converted according to standard >>> rules, if set and returns false - fatal error or exception is thrown. >>> >>> The implementation should be simpler and more efficient than using >>> declare(). >>> >>> Thanks. Dmitry. >>> >> >> This ruins portability with third party libraries completely. >> > > Not completely, because checker may be smart enough to return "true" for > third party files. > > <?php > set_strict_type_checker(function ($class_name, $function_nume, > $arg_num,$expected_type, $value, $file, $line) { > if (!my_own_file($filename)) { > return true; > } > ... > return false; > }); > include("index.php"); > ?> > > And you won't have to modify each file in your project adding > declare(strict_types=1). > Yes, but you need a mechanism for each third party library to register their typechecker code and then build a generic type checker system using the right checks for the right library. This will produce really slow code considering it will trigger this on every argument. Also i find declare(strict_types=1) is already adding another stack in my mind to think about, now having to think about every file/lirary having a different kind of validation makes it even more complicated. Additionally it destroys the AOT compile benefit of static type hints, since you cannot compile code down to C again, because the conversion/validation is not necesarily deterministic. > > Thanks. Dmitry. > > >