identifier :: TokenParser String
identifier = token go P.<?> "identifier"
  where go (Name s) = Just s
        go _        = Nothing
identifier :: TokenParser String
identifier = token go P.<?> "identifier"
  where go (Name s) = Just s
        go _        = Nothing
identifier = token go P.<?> "identifier"
  where go (Name s) = Just s
        go _        = Nothing