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Date: Thu, 16 Jul 2015 10:01:37 -0600
Message-ID: <CAFMT4Noxjp3+1t+oz1_bFUJR5nHx+KGLA6+YzJvm4SaqMYpU+w@mail.gmail.com>
To: Rowan Collins <rowan.collins@gmail.com>
Cc: PHP Internals <internals@lists.php.net>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [PHP-DEV] Consolidation of Traversable and array operations
From: levim@php.net (Levi Morrison)

On Thu, Jul 16, 2015 at 9:42 AM, Rowan Collins <rowan.collins@gmail.com> wrote:
> Levi Morrison wrote on 16/07/2015 16:23:
>
>> People have talked about creating types like so:
>>
>> type Iterable = array | Traversable;
>>
>> which could then be used as normal:
>>
>> function foo(Iterable $f);
>
>
> I kind of like this idea.
>
>> Why special case a pseudo-type if we can have a generic
>> way of making them in user-land?
>
>
> Well, for the same reason as large amounts of the core library exist (and
> PHP's is small compared to some): standardisation and ease of use. I think
> "array | Traversable" is a common enough use-case that it deserves a
> built-in name, even if a userland naming system is available.

I assume if `type Iterable = array | Traversable` can be built in
user-land then it will be done using the same mechanisms in core
(meaning it wouldn't be a special case or one-off type).