Improvement to switch-case statement

[John Reimer]

Hello Yigal,

> Mike James wrote:
> 
>> Just an idea that could improve Ds switch-case statement - add an
>> elipsys as in object Pascal to allow case ranges.
>> 
>> switch (var) {
>> case 1:
>> \\ do something
>> break;
>> case 2..10:
>> \\ do something else
>> break;
>> }
>> What do people think?
>> 
>> -=mike=-
>> 
> vote--
> 
> IMO, either the switch statement should remain the low level
> (effiecient) construct as in C, or replaced by a general mechanism of
> pattern matching. your solution is kinda between the two above options
> and I don't see the point of it.
> 
> I'd personally prefer pattern matching to be added to D and the switch
> to be deprecated and eventually removed from the language.
> 


Well, the D switch statement has already abandoned the low-level C construct 
in that it allows for switching on strings.  I don't think there is a reason 
to believe that adding the range feature would mean a loss of efficiency.

I have to agree that this would appear to be a fairly simple and useful feature 
that exists in other "old" languages like Pascal and derivitives.  I'm not 
sure why it was left out in D, but I wouldn't be a bit surprised if the request 
has been made before.

On the other hand, it probably wouldn't be hard to implement a range as a 
compile time template (or plain) function inserted after the case statement:

case range(2,10): //

But then again... since array slices make use of "..", it seems a shame that 
it can't also be used in the case statement for a similar purpose.

-JJR