derivings :: HParser [Name]
derivings = 
    do  lexDERIVING
        ( do cls <- tycls
             return [cls] )
          <|> (
          do lexLPAREN           
             clss <- tycls `sepBy` lexCOMMA
             lexRPAREN
             return clss )
derivings :: HParser [Name]
derivings = 
    do  lexDERIVING
        ( do cls <- tycls
             return [cls] )
          <|> (
          do lexLPAREN           
             clss <- tycls `sepBy` lexCOMMA
             lexRPAREN
             return clss )
derivings = 
    do  lexDERIVING
        ( do cls <- tycls
             return [cls] )
          <|> (
          do lexLPAREN           
             clss <- tycls `sepBy` lexCOMMA
             lexRPAREN
             return clss )