boolBinop :: (LispVal -> ThrowsError a) -> (a -> a -> Bool) -> [LispVal] -> ThrowsError LispVal
boolBinop unpacker op args = if length args /= 2 
                             then throwError $ NumArgs 2 args
                             else do left <- unpacker $ args !! 0
                                     right <- unpacker $ args !! 1
                                     return $ Bool $ left `op` right
boolBinop :: (LispVal -> ThrowsError a) -> (a -> a -> Bool) -> [LispVal] -> ThrowsError LispVal
boolBinop unpacker op args = if length args /= 2 
                             then throwError $ NumArgs 2 args
                             else do left <- unpacker $ args !! 0
                                     right <- unpacker $ args !! 1
                                     return $ Bool $ left `op` right
boolBinop unpacker op args = if length args /= 2 
                             then throwError $ NumArgs 2 args
                             else do left <- unpacker $ args !! 0
                                     right <- unpacker $ args !! 1
                                     return $ Bool $ left `op` right