gistfile1.txt

Main.hs:99:23:
    No instance for (MonadError
                       (String -> LispVal -> LispError) ((->) [Char]))
      arising from a use of `throwError'
    Possible fix:
      add an instance declaration for
      (MonadError (String -> LispVal -> LispError) ((->) [Char]))
    In the expression: throwError TypeMismatch "boolean" result
    In a case alternative:
        otherwise -> throwError TypeMismatch "boolean" result
    In a stmt of a 'do' block:
      case result of {
        Bool False -> eval alt
        Bool True -> eval conseq
        otherwise -> throwError TypeMismatch "boolean" result }