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Date: Mon, 2 Feb 2015 21:15:47 +0100
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Subject: AW: [PHP-DEV] What do we need strict scalar type hints for?
From: php@tutteli.ch ("Robert Stoll")


> -----Urspr=C3=BCngliche Nachricht-----
> Von: Lester Caine [mailto:lester@lsces.co.uk]
> Gesendet: Montag, 2. Februar 2015 21:06
> An: internals@lists.php.net
> Betreff: Re: [PHP-DEV] What do we need strict scalar type hints for?
>=20
> On 02/02/15 09:12, Dmitry Stogov wrote:
> > could you please write down few use cases, when strict scalar type
> > hints are really useful.
>=20
> Do we NEED strict scalar type control ... No Are there situations =
where strict scalar type control may be useful ...Yes Can a
> library be built ONLY using strict scalar type control ... Maybe ... =
provided that it only requires a set of data that can be 'strict'
>=20
> Much has been made of the idea that automatically causing errors when =
a wrong scalar type has been passed will simplify
> things, and in some cases that may be true, A few examples have been =
thrown up which suggest that integer values are a
> magic bullet when dealing with time or currency for example, but only =
some elements of that can easily be constrained to
> integers, other parts will require float or even string.
> When there is an error in any of this would one not expect any good =
library to produce a sensible set of error messages? A
> generic 'value not integer' needs to be augmented, so error checking =
against those elements that may be constrained
> would be mixed with error checking with the more weakly typed elements =
anyway?
>=20
> I can see that for some cases there may be an advantage but would it =
not be better to provide something that can act as a
> validity check against any input rather than some limited set of data? =
One 'class' that can identify where a scalar can be
> constrained or give a more relaxed result when required ... rather =
than having one rule for one and one for the other?
>=20
> --
> Lester Caine - G8HFL

Nobody would stop you from implementing a utility class Money or =
likewise and providing a better error message instead of using int if =
PHP would be strict only (what is not proposed in the RFC anyway). You =
could also just omit the type hint, it is entirely up to you.=20
There are plenty of strongly typed languages out there which work very =
well without the mentioned lack of specific error messages for each =
individual use case.
And btw. PHP is strict for array and class type hints as well  - of =
course you can also omit those type hints.=20