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Date: Mon, 14 Jul 2014 20:09:51 +0100
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To: PHP internals <internals@lists.php.net>
Subject: Re: [PHP-DEV] [RFC] Scalar Type Hinting With Casts (re-opening)
From: ajf@ajf.me (Andrea Faulds)


On 14 Jul 2014, at 13:58, Andrea Faulds <ajf@ajf.me> wrote:
>=20
> One of the issues with the RFC as it stands is how to handle bool =
casting. While int, float and string only allow lossless casting (with =
the exception of objects, but we can=92t really do anything about that), =
bool=92s behaviour at the moment is quite different. I don=92t think it =
makes sense so I won=92t discuss the current behaviour, only possible =
new ones.


> Another option is go completely strict and allow only boolean values, =
failing everything else. This would be unlike the int, float and string =
hints, which are flexible and cast, but would be more helpful for =
catching bugs. However, not casting at all isn=92t very =93PHP-like=94, =
and forcing people to manually cast with (bool) might not be ideal. If =
we were to go for this one, I might also accept objects casting to bool =
(which the default handler does), because I don=92t want to stop =
extension developers from making bool-like objects if they so please.

I=92ve made the patch and RFC do this, at least for the time being. I=92m =
still not really decided, nor is Anthony. The main advantage of being =
completely strict is that it=92s fully lossless; (bool)(string)$x =3D=3D=3D=
 $x where $x was a boolean, but (string)(bool)$x !=3D=3D $x where $x was =
a string. (Not necessarily, at least).

This would make it an oddball among the scalars as it=92s completely =
strict, and would require you to cast to bool explicitly in many cases=85 =
but at the moment it *seems* to be the most sensible option to me.

Still, we=92re both undecided.

--
Andrea Faulds
http://ajf.me/