Re: Exception handling within a compound statement?

[Fischlin Andreas]

Dear Phil,

Modula-2 has the philosophy of handling errors explicitly as the programer strives to write an error free code in the first place. The only exceptions that can be considered are numerical ones, such as an integer or real overflow etc., which are detected and handled by the underlying hardware and system settings. Depending on the current setting for the handling of such exceptions (tolerate or respond etc.) this results typically in a HALT of the Modula-2 program with some information on the causes of the exception and/or triggering of a debugger.

Hope this helps.

Sincerely yours,

Andreas Fischlin

ETH Zurich

Prof. em. Dr. Andreas Fischlin

Systems Ecology - Institute of Biogeochemistry and Pollutant Dynamics

CHN E 24

Universitaetstrasse 16

8092 Zurich

SWITZERLAND

andreas.fischlin@env.ethz.ch

https://sysecol.ethz.ch/people/andreas.fischlin.html

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             Make it as simple as possible, but distrust it!

________________________________________________________________________

On 20 Dec 2023, at 04:20, Philip Munts <phil@munts.net> wrote:

Ada allows exception handling within each begin/end block, and
also allows a begin/end block inside a compound statement:

loop
 begin
   raise Program_Error;
 exception
   when Program_Error =>
     ...
 end;
end loop;

Does GM2 allow something similar, or can exceptions be caught
only at the procedure or module level?

I like to use exceptions to propagate errors in Ada embedded
real-time software, since they can be caught and handled
anywhere along the calling chain or just ignored to abort the
program.

If exceptions can only be caught at procedure or module level
on the way out to a program abort, they are much less useful
to me.

Phil

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