simple parser

SimpleParser.hs

module SimpleParser where
import Text.Parsec
import Data.Text as T
import Data.Char

type SimpleParser a b = Parsec [a] () b

parseMaybe :: Show a => (a -> Maybe b) -> SimpleParser a b
parseMaybe f = tokenPrim show (\s _ _ -> incSourceColumn s (sourceColumn s)) f

satisfy :: Show a => (a -> Bool) -> SimpleParser a a
satisfy f = parseMaybe (\x -> if f x then Just x else Nothing)

emptyLine :: SimpleParser Text Text
emptyLine = SimpleParser.satisfy (T.all isSpace) 

runSimpleParser :: SimpleParser a b -> [a] -> Maybe b
runSimpleParser p stream =
  case runParser p () "" stream of
    Left _ -> Nothing
    Right r -> Just r

execSimpleParser :: SimpleParser a b -> [a] -> b
execSimpleParser p stream =
  case runParser p () "" stream of
    Left _ -> error "parser failed"
    Right r -> r