Диссертация Ben'а Lippmeier'а, создателя Disciple: "Type Inference and Optimisation for an Impure World":
http://cs.anu.edu.au/~Ben.Lippmeier/project/thesis/thesis-lippmeier-sub.pdf

"If I were to distill this thesis into one single point, it would be that the distinction between “pure” and “impure” languages is an artificial one. As we can express information about effects and mutability directly in the type system, using a standard framework, the difference between pure and impure is no greater than the difference between Bool and Float."

Также радует глава "Why destructive update matters".

Короче, нафиг монады, эффекты рулят