On 2011-03-19 13:16:02 -0400, dsimcha <dsim...@yahoo.com> said:
* "A goto from inside the parallel foreach loop to a label outside the
loop will result in undefined behavior." Would this be a bug in dmd?
No, it's because a goto of this form has no reasonable, useful
semantics. I should probably mention in the docs that the same applies
to labeled break and continue.
I have no idea what semantics these should have, and even if I did,
given the long odds that even one person would actually need them, I
think they'd be more trouble than they're worth to implement. For
example, once you break out of a parallel foreach loop to some
arbitrary address (and different threads can goto different labels,
etc.), well, it's no longer a parallel foreach loop. It's just a bunch
of completely unstructured threading doing god-knows-what.
Therefore, I slapped undefined behavior on it as a big sign that says,
"Just don't do it." This also has the advantage that, if anyone ever
thinks of any good, clearly useful semantics, these will be
implementable without breaking code later.
I think an improvement over undefined behaviour would be to throw an exception.
Also, what happens if one of the tasks throws an exception?
--
Michel Fortin
michel.for...@michelf.com
http://michelf.com/
