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Date: Thu, 24 Jul 2014 11:03:37 +0200
Message-ID: <CAEZPtU6=fFUPL20t9Tvm8w8Sgw_vswRfbZSG+X+OFNRLH4MwAg@mail.gmail.com>
To: Patrick Schaaf <php@bof.de>
Cc: PHP internals <internals@lists.php.net>, Andrea Faulds <ajf@ajf.me>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [PHP-DEV] [RFC] Scalar Type Hinting With Casts (re-opening)
From: pierre.php@gmail.com (Pierre Joye)

On Thu, Jul 24, 2014 at 10:52 AM, Pierre Joye <pierre.php@gmail.com> wrote:
> On Thu, Jul 24, 2014 at 10:42 AM, Patrick Schaaf <php@bof.de> wrote:
>> Hi,
>>
>> there is, it seems, something missing from both the RFC and the
>> discussion, as far as I read it. Sorry if it came up before, it was a huge
>> amount of mails...
>>
>> How does the proposal affect method compatibility between
>> subclasses and baseclasses? Will two methods there, differing in the
>> scalar type annotations of one of their arguments, elicit STRICT
>> warnings, like object type annotations do?
>
> I think it should behave like class arguments do.

I should be more precise :)

say:

function i(integer $i)
function f(float $f)
function s(string $s)

$i = 12;
$f  = 1.234;
$s = "abcdef";

For integer arguments:

Works:
i($i);

Fails:
i($f);
i($s);
i(new StdClass);

float fails as the argument cannot be an integer without lost of
information. It is a mis-usage of this function argument and the
intend of the caller can only be guessed and can only lead to bugs.

For float:
Works:
f($i);
f($f);
integer is, if I take the class behavior as example, like a float,
same "interface", fully compatible.

Fails:
f($s);
i(new StdClass);

For string, every scalar should work as both float and integer are
easily converted to string, we can compare them to objects with a
__toString method. I could live with strict too here but implicit
string conversion makes sense here. Float precision setting is used
for the decimal precision.

Arrays and objects without __toString fails, obvioulsy.

Cheers,
-- 
Pierre

@pierrejoye | http://www.libgd.org