Exception Hierarchy [WAS: Re: Top 5]

[Jarrett Billingsley]

On Sat, Oct 11, 2008 at 5:04 PM, downs <default_357-line at yahoo.de> wrote:
> Sean Kelly wrote:
>> Andrei Alexandrescu wrote:
>>> downs wrote:
>>>
>>>> 3) the Exception/Error problem (they're different things, they
>>>> shouldn't inherit!)
>>>
>>> I think Exception should inherit Error.
>>
>> I personally dislike the use of "Error" to denote exceptions of any
>> sort.  To me, errors are what /cause/ exceptions to be thrown.  For this
>> reason, in Tango and druntime, "Exception" is defined as the top-level
>> class from which all exceptions should derive (imagine that), making it
>> equivalent to your "Error" object.
>>
>
> Errors are useful. There is a class of problems that should not be trivially recoverable, i.e. not if you don't know what you're doing.
>
> It's the class of problems that would not be caught in release mode.
>
> Why? Because if such problems are caught thoughtlessly, then the program behavior changes in release mode .. which is a big, BIG no-no.
>
> So ArrayBoundsError, AssertFailedError, and InvariantError are all valid, and should NOT be derived from Exceptions.

And by the same token, string-to-integer conversion methods should not
throw an irrecoverable error.  I'm looking at you, ConvError.