Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:81645
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain lsces.co.uk from 217.147.176.214 cause and error)
Message-ID: <54CFD8B3.9080208@lsces.co.uk>
Date: Mon, 02 Feb 2015 20:06:11 +0000
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0
MIME-Version: 1.0
To: internals@lists.php.net
References: <CA+9eiLuueVvYgT-fhCvzBSxzoDioinpc5Eok5OQtGDBG1FZM=w@mail.gmail.com>
In-Reply-To: <CA+9eiLuueVvYgT-fhCvzBSxzoDioinpc5Eok5OQtGDBG1FZM=w@mail.gmail.com>
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] What do we need strict scalar type hints for?
From: lester@lsces.co.uk (Lester Caine)

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.

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'

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?

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?

-- 
Lester Caine - G8HFL
-----------------------------
Contact - http://lsces.co.uk/wiki/?page=contact
L.S.Caine Electronic Services - http://lsces.co.uk
EnquirySolve - http://enquirysolve.com/
Model Engineers Digital Workshop - http://medw.co.uk
Rainbow Digital Media - http://rainbowdigitalmedia.co.uk