Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:88303
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain gmail.com designates 209.85.212.174 as permitted sender)
MIME-Version: 1.0
In-Reply-To: <55FB533F.7080301@gmail.com>
References: <55FB4791.4040807@gmail.com>
	<CAOsHV+tE_JCd05K8iTgRoEi40n_ryOJ0E0fqCESae9Vep9F=vw@mail.gmail.com>
	<55FB533F.7080301@gmail.com>
Date: Thu, 17 Sep 2015 18:27:45 -0600
Message-ID: <CAObuZdsw9jmxpTcUrVW=cib5Pnhg8R3CDfk23Aag7P8GNBTS+Q@mail.gmail.com>
To: Rowan Collins <rowan.collins@gmail.com>
Cc: PHP internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=047d7bb04fcac510fa051ffa99ef
Subject: Re: [PHP-DEV] Let's discuss enums!
From: derokorian@gmail.com (Ryan Pallas)

--047d7bb04fcac510fa051ffa99ef
Content-Type: text/plain; charset=UTF-8

I few questions wrt the rfc: https://wiki.php.net/rfc/enum

> An enum value is only equal to itself.
I'm not sure I agree. How then do I store the enum into a DB and compare it
after reading?
switch($db->query('select role from user where user_id = 123')->fetch()[0])
{
  case UserRole::Admin:
      include 'admin.php';
      break;
  case UserRole::User;
      include 'user.php';
      break;
  default:
      include 'login.php';
      break;
}
Would this not ALWAYS include login if UserRole is an enum (instead of a
final class with constants as I use now, which a switch like this will work
for)?  Is this only possible with the magic value method? In which case I'd
have to check the value method, something like case
UserRole::Admin->ordinal() (or name, or value or whatever)?

>  This means that if the name enum is used for a property, function,
method, class, trait or interface there will now be a parse error instead.
Surely, a property can be named enum, since it can be named other reserved
words, for example?
$ php
<?php
class Foo {
  public $function = 'callMe';
  public $trait = 'useMe';
  public $class = 'instantiateMe';
}
$f = new Foo();
var_dump(get_object_vars($f));

array(3) {
  'function' =>
  string(6) "callMe"
  'trait' =>
  string(5) "useMe"
  'class' =>
  string(13) "instantiateMe"
}


Also, I really like the idea of being able to type hint the enum in the
switch(UserRole) that was mentioned. Not sure I like the idea of an
implicit throw though, consider the UserRole above, I might have 10
different roles, but the current switch is only valid for 5 of those roles.
In this situation, if I add a default: return Auth::NotAuthorized; will
that supress the implicit fall throw? If so, how often will the implicit
throw really be hit? I know we have standards that all case statements must
have default statements, to make sure every case is handled, whether we
foresaw it or not.

--047d7bb04fcac510fa051ffa99ef--