DIP33: A standard exception hierarchy - finally blocks not executed for Errors

[Don]

On Monday, 1 April 2013 at 20:58:26 UTC, Walter Bright wrote:
> On 4/1/2013 4:08 AM, Lars T. Kyllingstad wrote:
>> It's time to clean up this mess.
>
>
> As for why finally blocks are not executed for Error 
> exceptions, the idea is to minimize cases where the original 
> error would now cause an abort during the unwinding process. 
> Catching an Error is useful for things like:
>
> 1. throw the whole plugin away and restart it
> 2. produce a log of what happened before aborting
> 3. engage the backup before aborting
> 4. alert the operator that the system has failed and why before 
> aborting
>
> Unwinding is not necessary for these, and can even get in the 
> way by causing other failures and aborting the program by 
> attempting cleanups when the code is in an invalid state.

I think that view is reasonable, but then I don't understand the 
reason to have Error in the first place! Why not just call some 
kind of abort() function, and provide the ability to hook into it?

BTW, I actually went to quite a lot of trouble to make stack 
unwinding work correctly for Errors on Windows. It really wasn't 
easy.