A monad that uses GADTs and continuations to replicate what it is like to program in an imperative language like C, Java or Go with "return", "for", "break", "continue", and mutable references. In Version 2: Single return function: return' A Go language style defer' primitive. Proper compiler errors when break' and continue' are used incorrectly Note: Version 2 has a very different internal structure from version 1, and thus there will likely be type signature conflicts. For more information see: Examples on github http://github.com/mmirman/ImperativeHaskell/blob/master/Main.hs The relevant blog post http://kormacode.blogspot.com/2011/11/c-style-haskell_10.html