Comment by tromp

Lennart Augustsson once wrote the least-Haskell Haskell program, amazingly without the help of a preprocessor:

https://augustss.blogspot.com/2009/02/regression-they-say-th...

And to answer the question in the top comment:

https://hackage.haskell.org/package/BASIC-0.1.5.0/docs/Langu...