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Date: Thu, 24 Dec 2015 15:08:51 -0800
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To: =?UTF-8?B?QnJvbmlzxYJhdyBCaWHFgmVr?= <after89@gmail.com>
Cc: PHP internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Multicatch RFC proposal
From: pollita@php.net (Sara Golemon)

On Thu, Dec 24, 2015 at 2:40 PM, Bronis=C5=82aw Bia=C5=82ek <after89@gmail.=
com> wrote:
> I've just created an RFC draft for catching multiple exception types
> in one catch statement:
> https://github.com/bronek89/php-multicatch-rfc
>
> I wrote RFC on github to check if there is any positive response from com=
munity.
>
> Basically it introduces possibility to write code such as:
>
> try {
>     // ...
> } catch (DbException | ResourceNotFoundException $e) {
>     throw new HttpException("not found", 404, $e);
> } catch (\Throwable $e) {
>     throw new HttpException("fail", 500, $e);
> }
>
> Provided patch is my first experience with PHP source code, so it
> could be not perfectly written (or simply poor ;-) ) .
>
> What do you think about introducing that kind of feature into PHP?
>
I think introducing union types should be a prerequisite for this as
we don't want the much more widely impactful feature of arg/return
type hinting to be constrained by syntax we choose here (and making
them inconsistent would be even worse).

That said, from a general principle point of view, it certainly
doesn't seem unreasonable.  In an own-codebase one would probably use
interfaces, have each exception implement the the common denominator
(INotFound or what-have-you), but in a world of foreign components
that's not always practical.

On the other hand, one could just catch a throwable and use a pattern like =
this:

} catch (\Throwable $e) {
  switch (true) {
    case ($e instanceof DbException):
    case ($e instanceof ResourceNotFoundException):
      throw new HttpException("not found", 404, $e);
    default:
      throw new HttpException("fail", 500, $e);
  }
}

So I'm not personally going to get super excited about it, even if I
would vote in favor.

-Sara