Re: Opinions: exceptions in user oct files

[John W. Eaton]

On 05/02/2017 03:07 AM, Olaf Till wrote:
> On Mon, May 01, 2017 at 01:39:22PM -0700, Mike Miller wrote:
> >  - Should Octave catch any unknown exception object and turn it into a
> >    general error message, preventing the interpreter from a hard exit?
> >
> >  - Or should Octave require that user code not throw any exceptions
> >    other than the ones that Octave knows how to handle?
>
> I think the latter is better, maybe with the addition that Octave
> attempts a core dump.
>
> The thing is that Octave doesn't know the consequences of the cause
> for the uncaught exception in user code. If one of the consequences
> is, e.g., a memory leak, the faulty user code could eat up the memory
> if called in a loop with try-catch.

I don't see that it's any worse than an immediate crash because of an 
unhandled exception.

If I understand correctly, Mike was suggesting a generic catch block at 
the top level, which would then issue an error message and return to the 
command prompt.  At that point one could choose to continue or exit. 
The error message might say something like "Octave encountered an 
unknown exception.  This may be a bug in an external library, or in 
Octave itself.  You may wish to save your work and restart Octave."

jwe