A Poor Man's Concurrency Monad

Without adding any primitives to the language, we define a concurrency monad transformer in Haskell. This allows us to add a limited form of concurrency to any existing monad. The atomic actions of the new monad are lifted actions of the underlying monad. Some extra operations, such as fork , to initiate new processes, are provided. We discuss the implementation, and use some examples to illustrate the usefulness of this construction. 1 Introduction The concept of a monad (Wadler, 1995) is...