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Monads and delimited control are very closely related, so it isn’t too hard to understand them in terms of one another. From a monadic point of view, the big idea is that if you have the computation m >>= f, then f is m’s continuation. It’s the function that is called with m’s result to continue execution after m returns.

If you have a long chain of binds, the continuation is just the composition of all of them. So, for example, if you have

m >>= f >>= g >>= h

then the continuation of m is f >=> g >=> h. Likewise, the continuation of m >>= f is g >=> h.

@phadej
phadej / overlap.hs
Created July 1, 2016 09:56
OverlappingInstance workarounds
{-# LANGUAGE CPP #-}
{-# LANGUAGE ScopedTypeVariables #-}
{-# LANGUAGE FlexibleInstances, FlexibleContexts #-}
{-# LANGUAGE DataKinds, GADTs, KindSignatures, TypeOperators, UndecidableInstances #-}
#if __GLASGOW_HASKELL__ < 708
#error "requires GHC 7.10 or newer"
#endif
module Main (main) where