Ok, whipped up a quick readme. GitHub - yxhuvud/nest: Streamlined grouping of fibers focused on structured concurrency · GitHub
What is still missing is a: Stitching backtraces so that they are followable across nestings, and b: cancelations/deadlines in all its forms. Of those a is solvable and b require solutions in crystal itself. And maybe a smarter solution for recursive work is necessary. The current design for backpressure is for when all work is known up front.
EDIT: Created a separate topic in Nest - a shard for simple structured concurrency . Any comments go there, please.