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From: "Randy Brukardt" <randy@rrsoftware.com>
Newsgroups: comp.lang.ada
Subject: Re: Running a preprocessor from GPS?
Date: Thu, 30 Jul 2015 13:46:11 -0500
Organization: Jacob Sparre Andersen Research & Innovation
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Xref: news.eternal-september.org comp.lang.ada:27234
Date: 2015-07-30T13:46:11-05:00
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"EGarrulo" <egarrulo@gmail.com> wrote in message 
news:b68e14e7-e304-4220-81f5-67a88cef5767@googlegroups.com...
...
>> Do you mean that exceptions of Ada cannot be used for indirecting
>> non-local control flow with the help of exception objects?
>
>Exceptions in Ada cannot carry contextual information, nor they
>can be chained (albeit you could hack them to do both).

Huh? Every Ada implementation has some sort of contextual information in the 
Exception_Occurrence. The language doesn't try to specify what is available 
there, because that would necessarily prevent better implementations. (For 
instance, Janus/Ada includes a subprogram traceback in the 
Exception_Occurrence.)

I'm not sure what you mean by "chained". Reraise works (and does not erase 
the context in Janus/Ada, perhaps it does in other implementations).

> Where is the usefulness of knowing that something has gone awry,
> without any context?  For example: "'File not found?' What file
> was the program trying to open, and why?"

Again, every real Ada implementation provides that information in the 
Exception_Message. Trying to specify that in a language standard would have 
been a never-ending task, so it's implementation-defined. But implementers 
don't intentionally make their implementations useless...

                          Randy.