Article

From:
To:
Pete d'Oronzio
Subject:
Re: Exceptions vs Error codes
Newsgroup:
borland.public.delphi.objectpascal

Re: Exceptions vs Error codes

In article <3b7d8864$2_1@dnews>
	"Pete d'Oronzio" <‚úČpdmagic.com> wrote:

> > Why else the "on E:<exceptionclass>"
> > handling sub-statements. Why else a 'try' part at all, not just implicit
> > coverage by the next downstream "except-end" block.
> > Kristofer
> >
> 
> Yes. That's kind of what's been running through my mind.  Were exceptions
> just put there to perform the same function as a safety net for a flying
> trapeze artist?  I doubt it.  That would a waste.   In mose cases, if a
> routine exits unhappily and returns the user to the main program loop,
> that's about as good as crashing and re-starting the program.  Who knows
> what state the system is in?

The programmer who wrote the rollback procedures, either explicitly with
try..except ... raise; end or implicitly with a try.. {commit}
finally..end block.

> The best arguments I've heard against using lots of exceptions are about
> resource use.  Frankly, that logic doesn't sit well with me as resources and
> speed seem to be less and less a concern.  Does anyone have any hard numbers
> about added code size, execution size or speed?  I'd be interested in
> hearing about that.

I wouldn't want to be executing thousands of exceptions a second in a
webserver, say.

> What it's boiling down to for me is:
> What if I write a routine that returns an error code.  Someone uses it, but
> doesn't handle the error code because "this is just a quick and dirty
> version".  A lot of "quick and dirty" code is updated to shipping without
> all the chances to catch errors being handled.  Exceptions seem the solution
> to that.  If my routine raised an exception, and something went wrong, at
> least the shipping code wouldn't go blindly on thinking that everything was
> ok.
> 
> A programmer must explicitly dismiss an exception, while an error code can
> be ignored by default.

I agree with you. The main reason why I'm in favour of exceptions is the
same reason I'm in favour of democracy; it's pretty miserable, but it's
the best thing we've found so far.

-- Barry
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Originally created by
Tamarack Associates
Tue, 07 Feb 2023 04:43:55 UTC
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