Why exceptions for error handling is so important

[deadalnix via Digitalmars-d]

On Tuesday, 13 January 2015 at 19:36:31 UTC, Marc Schütz wrote:
> On Monday, 12 January 2015 at 23:01:53 UTC, Ola Fosheim Grøstad 
> wrote:
>> On Monday, 12 January 2015 at 22:06:32 UTC, deadalnix wrote:
>>> No, Exception are a bail out mechanism. It is the, I have no 
>>> idea what to do about this mechanism.
>>
>> The way it is done in C++, yes.
>>
>>> If you put aside performance concerns, exceptions for control 
>>> flow also tend to make many code path implicit and makes for 
>>> very unreadable/unmaintainable code.
>>
>> But exceptions are control flow. There is no such thing as 
>> normalized control flow, all state changes implies "control 
>> flow". Think in terms of a state machine. You could just 
>> remove all variables and only have a big state machine 
>> (assuming finite dimensions). Every single state transition 
>> implies flow of control.
>>
>> The control flow you see in the source code is just the 
>> programmer's "rendition" of control flow. Exceptions is a 
>> mechanism for getting cluttering resolution out of that 
>> rendition to make the code more readable and maintainable. The 
>> goal is to retain the meat of the computation and remove the 
>> noise.
>>
>> Or to put it differently, there are many ways to write the 
>> same function. Good use of exceptions removes the clutter and 
>> leaves the things you care about visible. It's a mechanism, 
>> not a moral issue or a religion.
>>
>> So there is nothing wrong with throwing HTTPStatus(409) or 
>> HTTPStatus(201), even though it returns state to the 
>> environment. If that means the code is more maintainable and 
>> more likely to be correct, then that is good use of the 
>> mechanism.
>
> I usually don't do this, but I really need to post a "+1" here:
>
> +1

Too bad you chose to do this on a bad strawmman.