blah :: Type + blah :: Type is gonna get parsed as blah :: (Type + blah :: Type)...

ben0x539 on Oct 27, 2013 | parent | context | favorite | on: Write yourself a Scheme in 48 hours: A Haskell Tut...

blah :: Type + blah :: Type is gonna get parsed as blah :: (Type + blah :: Type), just add more parens there. Also, you need to convert the result back to a string before calling putStrLn.