It's true that monads and delimited continuations are equivalent, but what we have here aren't any delimited continuations but what's known as multi-prompt deli

It's true that monads and delimited continuations are equivalent, but what we have here aren't any delimited continuations but what's known as multi-prompt delimited continuations, and I call them "scoped continuations" (http://blog.paralleluniverse.co/2015/08/07/scoped-continuations/ http://blog.paralleluniverse.co/2015/08/07/scoped-continuati...). Those compose well, and their pure-FP counterpart is algebraic effect systems (based on monads, but don't use monad transformers).