[racket-dev] Thread exit status

Hi all,

What do people think of the idea of threads preserving their exit status?

The exit status would be either
  - a raised exception, or
  - a normally-returned value, or
  - nothing as yet, because the thread is still running.

(thread-died-with-exception? thd) -> boolean?
  Returns #t if thd died from a raised exception, #f if thd exited
  through a normal return, or raises exn:fail:contract if thd hasn't
  exited yet.

(thread-exception thd) -> (or/c exn? false?)
  Returns the exception that killed thd, #f if the thread returned
  normally, or raises exn:fail:contract if thd hasn't exited yet.

(thread-result thd) -> any?
  Returns the value that thd's thunk returned, or raises
  exn:fail:contract if either thd hasn't exited yet or thd died from
  a raised exception.

The existing (thread-dead?) and (thread-dead-evt) would be used
unchanged. (Hmm - if a thread was killed, what would
(thread-died-with-exception?) return?)

Would it be difficult to implement? It'd require a change to the C code.

Regards,
  Tony