On 10/1/14, 4:00 PM, Sean Kelly wrote:
On Wednesday, 1 October 2014 at 22:42:27 UTC, Jeremy Powers via
Digitalmars-d wrote:
If you see "throws Exception" in java code chances are the code is
broken,
same as if you see "catch (Exception" - this tells you nothing about the
exception that happened, and hence you can do nothing with it. So you
either swallow (and silently break in many cases) or rethrow (and
break for things you needn't have). As mentioned, the standard way to
avoid this is to have a parent exception type appropriate to the
abstraction in the API, and throw subtypes in the implementation.
Among other things, this means you can change the implementation to
throw different exceptions without breaking any users (who will
already be catching the parent exception).
....while in Phobos, most of the subtyped exceptions were
eliminated a while back in favor of just always throwing
Exception.
My recollection is that was only talked about. Anyhow, one thing is
clear - as of now there are no clear idioms and successful techniques
for handling errors with exceptions (including the use of subtyping). --
Andrei
