This is my attempt at writing an understandable implementation of a subset of Haskell, in Haskell itself.
https://www.microsoft.com/en-us/research/wp-content/uploads/1992/04/spineless-tagless-gmachine.pdf https://homepages.inf.ed.ac.uk/wadler/papers/pattern/pattern.pdf http://moscova.inria.fr/~maranget/papers/ml05e-maranget.pdf