Yes, Haskell has green threads/co-routines. Racket /also/ has `thread` which is a co-routine but afaik you cannot pass the co-routine off to another native thr

Yes, Haskell has green threads/co-routines. Racket /also/ has `thread` which is a co-routine but afaik you cannot pass the co-routine off to another native thread and there are certain constraints passing data between different threads, similar to transferring ownership. I am not aware of the SBCL ecosystem to comment.