Re: [Discussion] is_string(), string type and objects implementing __toString()

Hi Ryan, On Wed, Mar 8, 2017 at 5:15 PM, Ryan Pallas <derokorian@gmail.com> wrote: > Sorry, accidently sent in the middle of typing that... > > On Wed, Mar 8, 2017 at 7:42 AM, Ryan Pallas <derokorian@gmail.com> wrote: >> >> >> >> On Wed, Mar 8, 2017 at 5:25 AM, Andrey Andreev <narf@devilix.net> wrote: >>> >>> Hi all, >>> >>> I submitted a GitHub PR* to allow objects implementing __toString() to >>> *optionally* pass is_string() validation. More verbose wording of my >>> motivation can be seen in the PR description, but here are the main >>> points: >>> >>> - Simpler way to do checks like: is_string($var) || >>> method_exists($var, '__toString') >>> - Can be used for stricter string parameter validation in >>> strict_types=0 mode (otherwise any scalar type is accepted) >>> >>> - Can be used for looser string parameter validation in strict_types=1 >>> mode (__toString() objects aren't accepted there) >>> - Regardless of the last 2 points, it is intentionally not limited to >>> parameter types >> >> >> If I understand correctly, you want the following to work: >> > declare(strict_type = 0); > function foo(string $bar) { > return $bar.'foo'; > } > > class Foo { > private $val; > public function __construct(string $val) { > $this->val = $val; > } > public function __toString() { > return $this->$val; > } > } > > echo foo(new Foo('this is ')); // this is foo > > But what happens if I change the foo function like: > function foo(string &$bar) { > $bar .= 'foo'; > } > > $foo = new Foo('object'); > foo($foo); > var_dump($foo); // will this be an instance of Foo, or the string > "objectfoo"?? > > If $foo remains an object in this scope, then the function is not modifying > its value. If it becomes a string, it's an unexpected change IMO. It is > probably fine in this case, but not in the case of a more complex object. This already works and while the reference thing is indeed ugly, the problems I have with it are different: 1) It also accepts every other scalar type. 2) It will not work with strict_types=1. 3) I want to do it mid-runtime, not just on function parameters. Cheers, Andrey.