Programming with algebraic effects and handlers, 2012. URL http:// math.andrej.com/2012/03/08/programming-with-algebraic-effects-and-handlers

Eff is a programming language based on the algebraic approach to computa-tional effects, in which effects are viewed as algebraic operations and effect han-dlers as homomorphisms from free algebras. Eff supports first-class effects and handlers through which we may easily define new computational effects, seam-lessly combine existing ones, and handle them in novel ways. We give a de-notational 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, coop-erative multi-threading, and others