Re: the state of the concurrency branch

[Stefan Monnier]

> I've also been periodically merging from trunk and running the test
> suite.

Thanks.

> This hasn't been too bad; though the changes to specpdl this
> year caused a few hiccups.

I'd have gladly helped.

> What would it take to merge the branch to trunk?

It sounds like it's close to ready for merge, indeed.
I'll take a closer look ASAP, but normally for such "core" changes, my
main concerns are:
- Backward compatibility: it's OK if some things break when you start
  using the new feature, but things should work as before as long as you
  don't use it.  Usually, to be convinced this is the case, the code
  should make it obvious.  The simplest way is sometimes conditional
  compilation, where we get back "the exact same code" as before if the
  flag is not set, but if we can get the "obvious backward
  compatibility" without resorting the conditional compilation, it's
  even better.
- The general design looks sound, so there's a good chance we'll be able
  to fix the problems that will show up without having to scrap it all
  and start over.
  

        Stefan