Computers for children

From: Ethan Dicks <erd_at_infinet.com>
Date: Fri Jan 15 18:29:55 1999

 
> >and while loops (I rarely use for's), but C really suffers from a lack of
> >a general error trapping mechanism that one can invoke to break out of
> >loops as required. Sometimes I think goto's are the answer but I can
> >never find an appropriate way to implement it.
>
> errflag := 0 /* is it := in C to assign a value? */

No. That's BLISS and BCPL, among others, IIRC. Drop the colon

> DO WHILE variable < end AND errflag = 0 {
> do stuff
> variable++ /* I think that increments a variable */

Yes.

> IF error THEN
> errflag := 1
> ENDIF
> LOOP
>
> IF errflag = 1 THEN
> do error processing
> ENDIF
>
> No, I'm not a C programmer (nor do I play one on TV).

Well... being a "perfessional", let me try...

Here's one way to do it that I have personally used:

  if (my_function())
    do error processing

my_function()
{
  /* I prefer for to while. It's all right here to see and debug */
  for (variable=0; variable < end; variable++) {
    do some work

    if (some error thing)
      return 1;
  }

  return 0;
}

If you insist on keeping the code in the higher-level function, there's
always the "break" statement.

In 15 years of C programming, I have yet to use a single goto. Yes, it
can simplify exception processing, but I've always found that if you
need a goto to simplify things, you didn't design it well enough the
first time around.

-ethan
Received on Fri Jan 15 1999 - 18:29:55 GMT