Examples

Simple URL parsing

Originally published on StackOverflow.

    import Text.Regex.Applicative

    data Protocol = HTTP | FTP deriving Show

    protocol :: RE Char Protocol
    protocol = HTTP <$ string "http" <|> FTP <$ string "ftp"

    type Host = String
    type Location = String
    data URL = URL Protocol Host Location deriving Show

    host :: RE Char Host
    host = many $ psym $ (/= '/')

    url :: RE Char URL
    url = URL <$> protocol <* string "://" <*> host <* sym '/' <*> many anySym

    main = print $ "http://stackoverflow.com/questions" =~ url