A Monadic Framework for Delimited Continuations

Kent Dybvig, Simon Peyton Jones, Amr Sabry

Submitted to Journal of Functional Programming

Delimited continuations are more expressive than traditional abortive continuations and they apparently require a framework beyond traditional continuation-passing style (CPS). We show that this is not the case: standard CPS is sufficient to explain the common control operators for delimited continuations. We demonstrate this fact and present an implementation as a Scheme library. We then investigate a typed account of delimited continuations that makes explicit where control effects can occur. This results in a monadic framework for typed and encapsulated delimited continuations which we design and implement as a Haskell library.