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Date: Wed, 13 Aug 2014 11:22:34 +0100
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Subject: Re: [PHP-DEV] [RFC] Disallow multiple default blocks in a single
 switch statement
From: rowan.collins@gmail.com (Rowan Collins)

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 = 30;
// ... arbitrary amount of code
switch ( $foo ) {
     case $bar:
     case 30:
}

-- 
Rowan Collins
[IMSoP]