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[Chris R. Miller]

Bruce Adams wrote:
> On Thu, 09 Oct 2008 01:08:54 +0100, Chris R. Miller 
> <lordsauronthegreat at gmail.com> wrote:
> 
>> Mike wrote:
>>> 4. Replace C-style switch with something modern and more D-like:
>>>  switch (x)
>>> {
>>>     case (0) foo();
>>>     case (1)
>>>     {
>>>         bar();
>>>         baz();
>>>     }
>>>     else throw new Exception("nope");
>>> }
>>
>> But that would break the techniques of a duff's device.  The existing 
>> syntax of a switch statement is more accurate to how it behaves, 
>> anyways.  It's like a more complex series of goto statements.
>>
>> http://en.wikipedia.org/wiki/Duff%27s_device
> 
> Duff's device is a perversion. The compiler should be left to perform
> those sorts of optimisations.

I really don't trust the compiler to make those optimizations.  What if 
someone makes a different compiler implementation and forgets to include 
the new implicit optimizations?

I also know people who work with real-time signal analysis algorithms, 
and the flexibility of the switch statement really aids their bottom 
line of performance.

>> http://en.wikipedia.org/wiki/Switch_statement
>>
>> Your proposal really makes it redundant with chains of if-else 
>> statements IMHO.
> 
> The difference is a switch might be optimised into a look-up table.
> A chain of if/then/else's requires a different kind of optimisation
> thought it might end up in the same form.
> 
> Though the main point is nothing to do with optimisation. Its about clarity
> of intent. A switch selects possible values of a single item and can
> be expected (in certain cases) to cover all cases. That is never true for
> if-then-else.

I was really thinking of if-if chains, sorry for the confusion, it was a 
brain-language-keyboard deficiency.

The switch statement as it currently is allows you a great degree of 
flexibility if you know how to (ab)use it.  If it's so dumb, don't use 
it.  I really am not amenable to the concept of changing the switch 
statement on such a fundamental level unless some clear advantage can be 
established that doesn't compromise existing functionality.