module RPGEngine.Parse.Core
( parseWith
, parseWithRest
, ignoreWS
) where

import Text.Parsec
    ( ParseError,
      anyChar,
      endOfLine,
      spaces,
      string,
      anyToken,
      choice,
      eof,
      manyTill,
      parse )
import Text.Parsec.String ( Parser )

------------------------------ Exported ------------------------------

-- A wrapper, which takes a parser and some input and returns a 
-- parsed output.
parseWith :: Parser a -> String -> Either ParseError a
parseWith parser = parse parser ""

-- Also return anything that has not yet been parsed
parseWithRest :: Parser a -> String -> Either ParseError (a, String)
--                     fmap (,) over Parser monad and apply to rest
parseWithRest parser = parse ((,) <$> parser <*> rest) ""
    where rest = manyTill anyToken eof

-- Ignore all kinds of whitespace
ignoreWS :: Parser a -> Parser a
ignoreWS parser = choice [skipComment, spaces] >> parser
    where skipComment = do{ string "#"; manyTill anyChar endOfLine; return ()}