A very interesting article,
Donnacha OisÃn Kidney and Nicolas Wu. 2026. Hyperfunctions: Communicating Continuations. Proc. ACM Program. Lang. 10, POPL, Article 7 (January 2026), 30 pages.
It has supplemental material and has been presented (and recorded) at POPL'26; for the sake of clarity, its abstract follows:
A hyperfunction is a continuation-like construction that can be used to implement communication in the context of concurrency. Though it has been reinvented many times, it remains somewhat obscure: since its definition by Launchbury et al., hyperfunctions have been used to implement certain algebraic effect handlers, coroutines, and breadth-first traversals; however, in each of these examples, the hyperfunction type went unrecognised. We identify the hyperfunctions hidden in all of these algorithms, and we exposit the common pattern between them, building a framework for working with and reasoning about hyperfunctions. We use this framework to solve a long-standing problem: giving a fully-abstract continuation-based semantics for a concurrent calculus, the Calculus of Communicating Systems. Finally, we use hyperfunctions to build a monadic Haskell library for efficient first-class coroutines.