Text.Parsec haskellStyle lexer is dangerous for some applications because of comment syntax

We sometimes need to keep "--". E.g., it appears in program texts of Program.Side.*

      -- FIXME : the program cannot start with a pre-decrement expression,
      -- since this has the potential to confuse the parser.
      -- imagine such a program stored inside a tuple.
      -- the parser for the "comma" will eat "-- ..." because it sees it as a comment