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Date: Thu, 11 Sep 2014 03:03:34 +0100
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References: <004d01cfcc63$e7e3ac40$b7ab04c0$@tutteli.ch> <3DB7DEC9-2F99-4DDB-95A9-70455E4BABCB@ajf.me> <54108D63.3070707@gmail.com>
To: Rowan Collins <rowan.collins@gmail.com>
Subject: Re: [PHP-DEV] make casts more strict in PHP 7
From: ajf@ajf.me (Andrea Faulds)


On 10 Sep 2014, at 18:41, Rowan Collins <rowan.collins@gmail.com> wrote:

> I think this came up during the previous discussion, and I actually =
think it would be quite nice to have some functions both to perform a =
"strict"/"safe" cast (and raise E_CATCHABLE_ERROR or perhaps throw =
TypeCastException), and to check if a variable *can* be thus cast =
(validating integers is unnecessarily complicated at the moment).
>=20
> Either:
> mixed safe_cast(mixed $var, string $type)
> boolean can_safe_cast(mixed $var, string $type)
> e.g.
> if ( can_safe_cast($_GET['i'], 'int') )
> $i =3D safe_cast($_GET['i'], 'int');
>=20
> Or, to avoid representing the type with a string arg, a whole set of =
functions:
> int safe_cast_int(mixed $var)
> boolean can_safe_cast_int(mixed $var)
> float safe_cast_float(mixed $var)
> boolean can_safe_cast_float(mixed $var)
> etc
>=20
> The first avoids creating so many new functions, but perhaps some =
constants should be defined for the argument, based on the values =
returned by gettype():
>=20
> PHP_TYPE_INT =3D "integer"
> PHP_TYPE_FLOAT =3D "double"
> PHP_TYPE_STRING =3D "string"
> PHP_TYPE_ARRAY =3D "array"
> PHP_TYPE_OBJECT =3D "object"
> PHP_TYPE_RESOURCE =3D "resource"
> PHP_TYPE_NULL =3D "NULL"
>=20
>=20
> Of course, we'd then need to agree exactly which casts are considered =
"safe"=85

You know, =93int=94, =93float=94, =93string=94 etc. aren=92t currently =
reserved words. We could add functions, or even make them reserved words =
and add internal functions (=E0 la isset), so int(=912=92), =
float(=912.0=92), string(=91test=92) etc.

Or perhaps class-like constructors? $a =3D new int('2'); ? Would kinda =
make sense given some people want to add methods to primitive types.

--
Andrea Faulds
http://ajf.me/