Interpreter of my own programming language called Dzuga written in Haskell as a JPP project.
It depends on two monad types: reader and exept.
In type checker i use both monads, i store exceptions on exept monad and map from identifier into type in reader one.
In interpreter i also use both monads, i use the same way of storing exceptions and i store map from identifier into specific value like bool, int, string, function and array.
You need to have: BNFC, ghci and make installed on your computer to run it.
makeMain.exe <path_to_dzuga_code>