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Date: Wed, 13 Aug 2014 13:02:34 +0200
Message-ID: <CAH-PCH6MyYvQrUCo3j3tAowDLdfRs38Ae=70UK7ag1r9RYFHVw@mail.gmail.com>
To: Rowan Collins <rowan.collins@gmail.com>
Cc: PHP Internals <internals@lists.php.net>
Content-Type: multipart/alternative; boundary=001a11339280b107f9050080b922
Subject: Re: [PHP-DEV] [RFC] Disallow multiple default blocks in a single
 switch statement
From: tyra3l@gmail.com (Ferenc Kovacs)

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On Wed, Aug 13, 2014 at 12:22 PM, Rowan Collins <rowan.collins@gmail.com>
wrote:

> Ferenc Kovacs wrote (on 13/08/2014):
>
>  sorry to jump in this late, but I'm not sure that it is a good idea to
>> only
>> reject the multiple default blocks but keep the ability to have the same
>> case multiple times:
>> http://3v4l.org/eZdPU
>>
>
> Multiple cases with the same value are a lot harder to prevent (if not
> impossible), because there is no requirement for the cases to be static, =
or
> of the same type. The spec actually calls this out with a couple of
> examples: https://github.com/php/php-langspec/blob/master/spec/11-
> statements.md#the-switch-statement
>
> It would be a bit awkward if this was a syntax error:
>
> switch ( $foo ) {
>     case 30:
>     case 30:
> }
>
> But this was fine:
>
> switch ( $foo ) {
>     case 30.0:
>     case 30:
>     case 10 * 3:
> }
>
> And this, which is completely undetectable at parse time:
>
> $bar =3D 30;
> // ... arbitrary amount of code
> switch ( $foo ) {
>     case $bar:
>     case 30:
> }
>
>
agree, and I thought about mentioning that, but I left that out, because
I'm not proposing to remove that ability (and I see more use-cases for that
as mentioned in my previous email) but stating that this patch would make
an arbitrary distinction between the normal and the default cases.

--=20
Ferenc Kov=C3=A1cs
@Tyr43l - http://tyrael.hu

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