bobc@attctc.Dallas.TX.US (Bob Calbridge) (10/07/89)
This is something that passed through my mind and I thought I's ask the
wizards here if it is possible. Though I've been working with C on and off
for a couple of years I don't get the chance to get deeply involved with
extremely complex programs. Therefore, when, from time to time, I see a
clever use of the flexibility of the language I get intrigued with the
possibilities. So I ended up with the question as to where a function
may be used in expressions. Mainly, can it be used anyplace that a variable
or a constant may? One example that came to mind, though I have no immediate
concept of how it might be used, is can a function be used as the argument to
a case statement? For example:
switch (expression) {
case f1(): do_this();
break;
case f2(): do_that();
and_that();
case f3(): while (youre_at(it)) {
take_out(the_garbage);
put_out(the_cat);
};
break;
case adnauseum: honk();
}
where f1...fn() may be functions that evaluate circumstances and return an
integer or get input from the user and return an integer. I have vague
ideas as to why something may be implemented this way, if it is even possible.
I just don't have an immediate need, just an immense curiosity. Is the
language that flexible or is it possible to violate this concept?
--
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= I know it's petty.......... =
- But I have to justify my salary! -
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=cpcahil@virtech.UUCP (Conor P. Cahill) (10/07/89)
In article <9604@attctc.Dallas.TX.US>, bobc@attctc.Dallas.TX.US (Bob Calbridge) writes: > switch (expression) { > case f1(): do_this(); > > where f1...fn() may be functions that evaluate circumstances and return an > integer or get input from the user and return an integer. This is not allowed. The expression in a case statement MUST be a constant expression. A function call is not a constant. It looks like you are back to the old if-then-else stuff. -- +-----------------------------------------------------------------------+ | Conor P. Cahill uunet!virtech!cpcahil 703-430-9247 ! | Virtual Technologies Inc., P. O. Box 876, Sterling, VA 22170 | +-----------------------------------------------------------------------+