Kannan Goundan wrote:
I've implemented this functionality in a hand-written parser (basically a hack that keeps track of whether the last read token was preceded by an EOL, without making EOL itself a token). Does anybody have ideas about how to do this with Parsec?
You can do exactly the same with Parsec: * create a lexer that yields a [Token], including EOL tokens; * write a function of type [Token] -> [(Token, Bool)] that discards EOLs and tells for each token whether it was preceded by a (now discarded) EOL; * write your pToken :: Token -> Parsec Token function (I omitted some type variables there) that recognises one (Token, Bool)-tuple from the input stream. Or, perhaps easier: * create a lexer that yields a [Token], including EOL tokens; * write a function of type [Token] -> [Token] that discards only those EOL tokens that aren't needed -- for example, those EOL tokens that occur when there are no open ['s, then parse those EOL's explicitly in your parser. Hope this helps, Martijn.