> > I was talking of the ErrTry/ErrCatch/ErrEndCatch block, and the ErrThrow
> > function. It seems reasonable to think that this is the lowest common
> > denominator, since it is the mechanism provided by the OS.
>
> Oh, *those*. I didn't realise anybody actually used them :-).
Despite of all the problems it raises (variables mysteriously changing if
you forget the 'volatile' keyword, important overhead...), it is the only
way to have exception-like mechanism in C. Unless I missed something...
> You're absolutely right: they're supplied by the operating system, so
> if you think Palm OS is one cohesive whole [...]
I've never thought such a thing ! :-)
> Okay, so you really do want to abort the sort immediately. Fair enough,
> but it's not something that's supported by SysQSort(), which isn't
> ErrException-safe. You do have the option of writing your own sort
> routine, at which point you have the opportunity to abort via any
> mechanism you like -- and you're sure to find a more efficient one than
> ErrorMgr exceptions.
Yes, I do want to abort the sort. As you suggested, some fatal error
condition can occurs in the comparison function. I think I'll write my own
SysQSort, it's simple, but it wastes space and time...
> Int16 cmp (void *a, void *b, Int32 other) {
> if (indicates_weve_already_failed (other))
> return (char *)b - (char *)a;
> else
> return do_the_real_lookup_and_cmp (a, b, other);
> }
I'm not sure, but I expect this won't work. I think the quicksort algorithm
behaves badly if you change the sorting order while processing, because it
may not be able to find a pivot point in the current partition. This will
probably make a pointer to read/write out of the bounds of the array, or
other bad thing.
Pascal
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