Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:92524
Return-Path: <mathieu@rochette.cc>
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Delivered-To: mailing list internals@lists.php.net
Received: (qmail 929 invoked from network); 20 Apr 2016 08:05:54 -0000
Received: from unknown (HELO lists.php.net) (127.0.0.1)
  by localhost with SMTP; 20 Apr 2016 08:05:54 -0000
Authentication-Results: pb1.pair.com smtp.mail=mathieu@rochette.cc; spf=pass; sender-id=pass
Authentication-Results: pb1.pair.com header.from=mathieu@rochette.cc; sender-id=pass
Received-SPF: pass (pb1.pair.com: domain rochette.cc designates 62.210.206.189 as permitted sender)
X-PHP-List-Original-Sender: mathieu@rochette.cc
X-Host-Fingerprint: 62.210.206.189 texthtml.net  
Received: from [62.210.206.189] ([62.210.206.189:47147] helo=texthtml.net)
	by pb1.pair.com (ecelerity 2.1.1.9-wez r(12769M)) with ESMTP
	id 2F/E2-14036-06837175 for <internals@lists.php.net>; Wed, 20 Apr 2016 04:05:53 -0400
Received: by texthtml.net (Postfix, from userid 65534)
	id 0C7B7232; Wed, 20 Apr 2016 08:05:48 +0000 (UTC)
Received: from [192.168.1.130] (stunnel_mail_1.mail_default [172.27.0.4])
	(Authenticated sender: mathieu@texthtml.net)
	by texthtml.net (Postfix) with ESMTPA id 6D9EF22F;
	Wed, 20 Apr 2016 08:05:46 +0000 (UTC)
To: Sara Golemon <pollita@php.net>, Mathieu Rochette <mathieu@texthtml.net>
References: <CADqTB_gUbfu91QRm1U0KyDjai8DKw7yCE6QxgUecy60oq3Zi8Q@mail.gmail.com>
 <CAKiSzdCO83XM0zqAeFnjQEMJvbd0yBmYAFnj0H6AtDumofVbkw@mail.gmail.com>
 <CAKiSzdCCEF=7OWtvZETG3bRoByCCLqEAEjuLW_H6m7MmDtJ8_g@mail.gmail.com>
 <CAFKaYMoQUUFLqgDjOHj3W0+a63u3s=vqnU5gWMCj0zvmvXFF5Q@mail.gmail.com>
 <3cc8a4c7-2640-11ae-a67b-06f909ac1e27@texthtml.net>
 <CAESVnVqCZnrbHa+5_tSYG70VyvGfpZoDM98bEst3pg36HahYEg@mail.gmail.com>
Cc: Dominic Grostate <codekestrel@googlemail.com>,
 Josh Di Fabio <joshdifabio@gmail.com>,
 PHP internals <internals@lists.php.net>,
 Ben Scholzen 'DASPRiD' <mail@dasprids.de>,
 Rasmus Schultz <rasmus@mindplay.dk>
Message-ID: <57173859.4080501@rochette.cc>
Date: Wed, 20 Apr 2016 10:05:45 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101
 Thunderbird/38.6.0
MIME-Version: 1.0
In-Reply-To: <CAESVnVqCZnrbHa+5_tSYG70VyvGfpZoDM98bEst3pg36HahYEg@mail.gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] [RFC:generics]
From: mathieu@rochette.cc (Mathieu Rochette)



On 20/04/2016 00:22, Sara Golemon wrote:
> On Tue, Apr 19, 2016 at 1:16 PM, Mathieu Rochette <mathieu@texthtml.net> wrote:
>> about the upper bounds, have you consider another way of describing the
>> constraints, eg:
>>
>> class Box<T> where T is Boxable
>>
>> this would allow multiple constraints, eg:
>>
>> class Collection<T> where T is Traversable, T is Countable
>>
> IMO, this sort of problem should be solved by combining this feature
> with union types, so you could have something like:
>
> class Collection<T as (Traversable | Countable)> {...
>
> And merely inherit the logic rules from that feature rather than
> inventing yet another one.
obviously if the union type rfc passes we don't need another way of 
expressing this.
that was only in the case it does not, I think having a way to have at 
least types intersection
is useful here (and I didn't event think about <T is A & B>)
>
>> can generic types be nested ?
>>
>> class Stuff<A, B is Something<A, string>>
>>
> I can't imagine why not...
just to be clear, it's not just nested generic. the A type have to be 
same in both "subtypes"
>
> For my part, I love the concept overall.  Generics are an important
> part of moving PHP towards comprehensive type-safety.  But then, you
> know how I feel about Hack. :)
>
> -Sara
>