[Haskell-cafe] why 'try' not work in parsec
ryani.spam at gmail.com
Sun Nov 23 04:47:29 EST 2008
On Sat, Nov 22, 2008 at 9:46 AM, Changying Li <lchangying at gmail.com> wrote:
> I read 'write yourself a scheme in 48 hours' and try to modify its code.
> now part of code is :
> parseList :: Parser LispVal
> parseList = liftM List $ sepEndBy parseExpr spaces
> <|> do char '('
> skipMany space
> x <- (try parseList) <|> parseDottedList
> char ')'
> return x
parseList is succeeding and returning (1); then "char ')'" is failing
(because the next character in the input is the '.'
More information about the Haskell-Cafe