Ary Borenszweig wrote:
Andrei Alexandrescu wrote:
Steve Teale wrote:
Daniel Keep Wrote:
Steve Teale wrote:
Daniel Keep Wrote:
Steve Teale wrote:
...
What is the point of class Throwable if you can throw any old
class object?
What class Throwable?
dmd\src\druntime\src\compiler\dmd\object_.d
-- Daniel
Ah.
Well, if I had to guess, I'd say it was because Throwable objects are
more useful than random objects of other types. Object doesn't give
you
msg, file, line, info or next.
-- Daniel
But doesn't it rather imply that if you want to be able to throw a
class, then it should be derived from Throwable?
Yes, a check should be added to that effect. Later on we need to
actually exploit that only certain types can be thrown in implementing
exception chaining.
What is exception chaining? Consider:
void weird()
{
scope(failure) throw new Exception1("hum");
throw new Exception2("ho");
}
The C++ model terminates the app when an exception is thrown while the
stack is unwound. Java (I was told without having checked) makes the
latest exception thrown the "main" exception, and you get to also
access the other exceptions by using primitives in class Exception. Is
that true?
You can't throw multiple exceptions in Java. What you can do is:
try {
...
} catch(SomeException e) {
throw new AnotherException(e);
}
and then AnotherException is thrown with "e" being it's inner exception,
and you can check that.
Anyhow, we should implement a model in D that allows such multiple
throws.
What for?
For allowing destructors to throw.
Andrei
