Article

From:
To:
Kristofer Skaug
Subject:
Re: Exceptions vs Error codes
Newsgroup:
borland.public.delphi.objectpascal

Re: Exceptions vs Error codes

In article <3b7f9bcc$1_1@dnews>
	"Kristofer Skaug" <‚úČskaug.demon.nl> wrote:

> atomicised operations focused on handling errors close to the source
> of error (for specific handling) can do with a lower degree of
> nesting. i.e.

Why do you need to handle the errors? If you really need to handle the
errors, then (IMO) the operations should be in completely separate
functions, so that you can eliminate the drudgery of handling the same
errors over and over again.

> try 
> [...]
> try
>   opN
> finally
>   cleanup / error handle opN
> end;
> 
> we discussed this approach before.

Still; if you were using return values for errors, your code would look
like:

  if not opN then   begin     // handle opN failing   end;   // clean up after opN
Not a whole lot different.
Another thing: your operations above are sequential; because you handle errors after each step, it seems to be implied that each step doesn't depend on the previous step completing (otherwise the small failure would prevent the completion of the larger transaction).
But then again, if you really really need to continue, to struggle through no matter how much coding around issues you need to do, then whether or not exceptions are present isn't going to make much difference; the code occupied with the struggle will dwarf any difference between error codes and exceptions.
If you feel it's cluttered, have you considered making your operations nested functions, like:
---8<--- procedure BigOp;
  procedure Op1;
    procedure TryOp1;     begin     end;
    function TryHarderOp1: Boolean;     begin     end;
  begin     try       TryOp1;     except       if not TryHarderOp1 then         raise;     end;   end;
  // ...
begin   Op1;   Op2;   // ...   OpN; end; --->8---
Just an idea; it works for me.
-- Barry
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Originally created by
Tamarack Associates
Tue, 07 Feb 2023 04:56:28 UTC
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