The Delphi Geek: Case .. else raise, again

Friday, May 11, 2007

Case .. else raise, again

Yesterday I used a really bad example which got most of my readers thinking about how most of the code could be optimized away. As that was not the idea behing my post, I decided to give a better example. This one is straight from the production code:

case mafWorkerOwner.PostToThread(MSG_AF_SCHEDULE_VIDEO, clonedBuffer) of
  mqpOK:
    Result := ClearError;
  mqpTimeout:
    Result := SetError(ERR_MXFFILTER_THREAD_TIMEOUT,
      'Timeout while sending message to the worker thread');
  mqpQueueFull:
    Result := SetError(ERR_MXFFILTER_QUEUE_FULL,
      'Cannot send message to the worker thread - queue full');
  else raise Exception.Create('TMXFAsyncFilter.ScheduleVideo: Unexpected PostToThread result');
end; //case PostToThread

Am I making more sense now?

Technorati tags: Delphi, programming, best practices

4 Comments:

Chris said...: It *was* clear first time around, even for would-be smart arses (or at least, should have been)...; 15:58
Jan Derk said...: It was clear to me too, but maybe because I do exactly what you do.; 21:08
stanleyxu said...: How about write a function instead of putting your raise directly there?

procedure UNHANDLED_CASE(const Msg: string);
begin
{$IFOPT C+} //debugger mode
raise ....
{$ENDIF}
end;

function UNHANDLED_CASE(const Msg: string; ExpectedValue: Boolean): Boolean;
begin
...
end;

function UNHANDLED_CASE(const Msg: string; ExpectedValue: Integer): Boolean;
begin
...
end;

And so on; 11:03
gabr said...: If you like it that way, why not.; 11:31