Vi vet ju alla numera att monader är en både vacker och enormt användbar abstraktion men nu är de dags att gå vidare och ta till sig de algebraiska effekterna. Andrej Bauer och Matija Pretnar har skrivit "Programming with Algebraic Effects and Handlers":        

Eff is a programming language based on the algebraic approach to computational effects, in which effects are viewed as algebraic operations and effect handlers as homomorphisms from free algebras. Eff supports first-class effects and handlers through which we may easily define new computational effects, seamlessly combine existing ones, and handle them in novel ways. We give a denotational semantics of eff and discuss a prototype implementation based on it. Through examples we demonstrate how the standard effects are treated in eff , and how eff supports programming techniques that use various forms of delimited con- tinuations, such as backtracking, breadth-first search, selection functionals, cooperative multi-threading, and others.