🚀 go-pugleaf

Kevlin A P Henney (Kevlin@two-sdg.demon.co.uk) wrote:
>Why? Given that an important feature of a switch statement is that the
>target labels are unique, how do you intend to determine this at compile
>time for runtime expressions?

The labels are unique because they are intended to be used as constants,
just like 'a' or 'z'.  Just like you do not change 'a' at run time, you
can not (or should not) change my constants either.  I guess I should say
I want to create my own constant 'literals', and be able to control the size.

>Sounds like enums to me -- you've got all the language you need to do the job.

I did use enums.  I switched to a class because it allows me to control
the size.  The type I had in mind is used very often.  Thus size and
efficiency is very important.  On many systems (especially 32 bit machiens),
sizeof(enum) == 4.  But, for my internal_type  sizeof(internal_type) == 1.
Thus, I can store four times as many data, and yet still have the operators
for convience.  The only problem was, I no long can use switch statements
like I could with enums.  I guess if I want speed, I have to use array
indexing.  But with large number of constants, the array will be large,
so I still lose storage space.  I just can't win.  :)  It would be great
if the switch could detect that my internal type was actually a 'char'
type and base the selection process on that.  I'm not sure how complicated
the compiler would be to do this.  But I think it is possible.  Maybe it
should be an optional feature in C++.
--jc
--
Jimen Ching (WH6BRR)      jching@aloha.com     wh6brr@uhm.ampr.org

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