On 19/02/2012 01:54, Jonathan M Davis wrote:
On Sunday, February 19, 2012 01:43:27 Ben Davis wrote:
- distinguish between 'bug' exceptions (e.g. null) and 'you're more
likely to want to catch this' exceptions (e.g. IO). Maybe the bug ones
should have been Errors, since people *usually* don't catch those (and
are certainly never required to). As it stands, Errors are reserved for
corrupt class files and other VM panic scenarios.
Well, in D, you'd use exceptions derived from Error (though null pointers
still result in a good ol' segfault). Java's situation is marred by the whole
thing with checked exceptions. D's basic is better in that regard, I think.
It's the lack of a proper exception hierarchy where we're worse.
Indeed, I'd noticed I was getting RangeErrors, not RangeExceptions :)
- make sure the 'lazy' approach is a good one: the less you type, the
fewer exceptions you catch, and the less likely you are to silence those
exceptions at runtime. Probably the main problem with the exception
hierarchy is that the short names tend to be the more general ones that
are more dangerous to catch indiscriminately.
You mean, make the standard exception names really long and ugly, and the more
specific ones short? e.g. Exception becomes something like
StandardExceptionThatYouReallyShouldBeCatchingCatchTheDerivedType whereas
specific exceptions are more like SpecifcEx (though that's a bit extreme)?
Well, while that's a good sentiment, the very nature of more specific
exceptions means that their namesj are likely to be more specific and therefore
longer (especially when you have descriptive names). So, I'm not sure that
that's ultimately all that reasonable, even if the basic idea is a good one.
LOL - yeah, there's a reason I didn't propose any actual names. It's not
an easy problem to solve. But I felt the psychology angle might not have
been covered and was worth mentioning all the same.
You could name the class "AllExceptions" though.
But as the insidious ones like off-by-ones are Errors (or segfaults),
it's definitely a much smaller problem in D than in Java.
