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Date: Thu, 1 Jan 2015 15:28:40 +0000
Cc: Zeev Suraski <zeev@zend.com>,
 PHP Internals <internals@lists.php.net>
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References: <41D5BB0B-73AF-488E-968D-90B2878E3178@ajf.me> <16d442a345cf2cbd4faac6d068c57343@mail.gmail.com> <CAEra97q-hNQScjX1RzVkrAhegGQx3GKRKV3JDjxJ=hay2oyXrg@mail.gmail.com>
To: Maxime Veber <nek.dev@gmail.com>
Subject: Re: [PHP-DEV] [RFC] Scalar Type Hints
From: ajf@ajf.me (Andrea Faulds)

Hi Maxime,

> On 1 Jan 2015, at 13:29, Maxime Veber <nek.dev@gmail.com> wrote:
>=20
> I was expected an RFC like this in PHP for a while. I'm happy somebody =
made one, thanks.

Glad to hear that.

> But something hit me in that. even if you can't give an objet, you can =
give any scalar type that will be cast.
> I'm not sure this behavior is very relevant.
>=20
> Actually if I ask for a string, why the user could be specify an int =
without getting error ?
>=20
> Consider the following PHP 5.6 code:
>=20
> function foo($a) {
>     if (!is_string($a)) {
>         throw new \Exception('You need to give a string');
>     }
> }
>=20
> Using your type hinting does not fix the problem of string checking =
because the value will just be cast if it's an integer. Ofc if the user =
give an object it's ok.
> But why not throw a message error in any cases ?

For various reasons, PHP has always been a weakly-typed language, so we =
allow conversions between scalar types when they make sense. An integer =
isn=E2=80=99t a string, sure, but it can be simply converted to one and =
the result makes sense, so I think that=E2=80=99s why we allow it. It =
would still error in some cases, like an object without __toString for a =
string parameter, or an array for an integer parameter.

Thanks.
--
Andrea Faulds
http://ajf.me/