[net.arch] how to handle range checking

jer@peora.UUCP (J. Eric Roskos) (09/24/85)

> What should the code do when a range-check occurs?  Print out an error
> message on ticker-tape & hang?  Do nothing?  A better analogy, perhaps,
> would be...

Well, since the example was MX missiles, I guess it should invoke the Ada
exception handler... the exception handler should then fix things up, and
continue execution... or run the "abort" procedures...

It's certainly better than having the missile overwrite some state variable
and go off course into a city somewhere because there was no checking.
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chuck@dartvax.UUCP (Chuck Simmons) (09/30/85)

> > What should the code do when a range-check occurs?  Print out an error
> > message on ticker-tape & hang?  Do nothing?  A better analogy, perhaps,
> > would be...

The real advantage to range checking comes when you are debugging and testing
your program.  With range checking, bugs in the code become immediately
apparent.  Without range checking, the code may run for quite some time
before it becomes obvious that something is terribly wrong.

When an error condition does occur, the program should abort as cleanly
and quickly as possible leaving as much information as it can for its
programmer to figure out what went wrong.  For some programs, it may be
possible to return to some known state and then continue processing.

-- chuck