Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:92485
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 209.85.214.196 as permitted sender)
MIME-Version: 1.0
Reply-To: bishop@php.net
Sender: bishop.bettini@gmail.com
In-Reply-To: <5716755E.1040807@gmail.com>
References: <CADFyporyFgnMgetcEj8FZUFs1Lbc_VidBsxg5jBE7J4_OFzKTQ@mail.gmail.com>
 <CA+kxMuTFfqHZa4sXNv=Cfcm8w6eHdkKSGYiPdUiTJ1DGd6_VQQ@mail.gmail.com>
 <CADyq6sJP_BYEmmTWzJ4OvhcM9uto2EY+vefZTKovAaKBA8hs7w@mail.gmail.com>
 <CAEYWF=6+t_Td5Gb4grOdkDogFZaEOxKs7FYonK9OsOuuybOncQ@mail.gmail.com>
 <571581C7.7010901@gmail.com> <CAEYWF=4fTeYn9oDr_x+i6G2=boyspX07d8S2SH1A-ZdBqP_ZMA@mail.gmail.com>
 <571589AF.3090502@gmail.com> <CAEYWF=48DmTT8t6TL1n2euosE1cozVs==bfCsbHsN4WiGPvgig@mail.gmail.com>
 <5716755E.1040807@gmail.com>
Date: Tue, 19 Apr 2016 15:18:50 -0400
Message-ID: <CAEYWF=5teWVEd=BQsT4w-d_ssxfhRULmjBEfHOCSf_VkGGgakw@mail.gmail.com>
To: Stanislav Malyshev <smalyshev@gmail.com>
Cc: PHP internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=047d7b5d5ffca4a5ea0530db5afc
Subject: Re: [PHP-DEV] [VOTE] Catching Multiple Exception Types
From: bishop@php.net (Bishop Bettini)

--047d7b5d5ffca4a5ea0530db5afc
Content-Type: text/plain; charset=UTF-8

On Tue, Apr 19, 2016 at 2:13 PM, Stanislav Malyshev <smalyshev@gmail.com>
wrote:

> Hi!
>
> > namespace Application;
> > function log(Eloquent\Collection | Haldayne\Map $entity) {
> >     $logger->log($entity->toArray());
> > }
>
> This is bad design. It assumes that two completely unrelated classes
> have the same function and it means the same.


Both of these exist in the wild, and both have identical function wrt
toArray: reducing a set of collection-like things to an array of arrays.


> If it's indeed true, we
> have a way to express it. It's called "interface".


Except these two are in separate libraries that cannot share an interface.


> > "Ugh, this is much easier in multi-catch. If only functions took
>
> multiple types, this would be much simpler to write."
>
> And it would be completely wrong, abuse of typing. If you mean to say
> "anything that has [toArray] method", you should either have interface or
> just get rid of the strictness and duck-type it and rely on PHP to throw
> exception if anything happens. Otherwise it is just a sloppy design.
>

An interface is not possible: separate libraries. Duck-typing is not
appropriate: only these two specific classes are supported.

Union types solve certain problems better than equivalent run-time checks.
Multi-catch solves certain *other* problems better than equivalent
many-catch. They are orthogonal, but the syntax is similar: *"into this
block, accept this type or this type or ...."*

I contend that this apparent similarity must be consistent, lest we earn
another sadness.

--047d7b5d5ffca4a5ea0530db5afc--