HaScalaM

It converts (textually) to and fro between Haskell and Scalameta ASTs.

It is fairly complete as far as Scalameta coverage is concerned. It starts with "constraint" classes corresponding to Scalameta traits, goes through types corresponding to OOP, and ends with wrapper types that have Show instances.

The disadvantage is that constructors are "doubled", e.g., "TDo (SmDoT" is required, because "TDo" involves type equality, while "SmDoT" only uses type constraints. ("T" stands for "term".)

It is used here at the metaprogramming level to convert to and fro between Scala and Haskell.