src/Text/Pandoc/CSS.hs · typeable/pandoc

git.iko.soy/typeable/pandoc

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1module Text.Pandoc.CSS ( foldOrElse,

2 pickStyleAttrProps

3 )

4where

6import Text.Pandoc.Shared (trim)

7import Text.Parsec

8import Text.Parsec.String

10ruleParser :: Parser (String, String)

11ruleParser = do

12 p <- many1 (noneOf ":") <* char ':'

13 v <- many1 (noneOf ":;") <* (optional $ char ';') <* spaces

14 return (trim p, trim v)

16styleAttrParser :: Parser [(String, String)]

17styleAttrParser = many1 ruleParser

19orElse :: Eq a => a -> a -> a -> a

20orElse v x y = if v == x then y else x

22foldOrElse :: Eq a => a -> [a] -> a

23foldOrElse v xs = foldr (orElse v) v xs

25eitherToMaybe :: Either a b -> Maybe b

26eitherToMaybe (Right x) = Just x

27eitherToMaybe _ = Nothing

29pickStyleAttrProps :: [String] -> String -> Maybe String

30pickStyleAttrProps lookupProps styleAttr = do

31 styles <- eitherToMaybe $ parse styleAttrParser "" styleAttr

32 foldOrElse Nothing $ map (flip lookup styles) lookupProps