Text.Megaparsec.ByteString

Convenience definitions for working with ByteString.

Documentation

type Parser = Parsec ByteString

Different modules corresponding to various types of streams (String, Text, ByteString) define it differently, so user can use “abstract” Parser type and easily change it by importing different “type modules”. This one is for strict bytestrings.

parseFromFile :: Parser a -> String -> IO (Either ParseError a)

parseFromFile p filePath runs a strict bytestring parser p on the input read from filePath using readFile. Returns either a ParseError (Left) or a value of type a (Right).

main = do
  result <- parseFromFile numbers "digits.txt"
  case result of
    Left err -> print err
    Right xs -> print (sum xs)