indexfilter.hs

import Text.Pandoc.JSON
import Text.Parsec
import Control.Applicative
import Data.Monoid

main :: IO ()
main = toJSONFilter index

index :: Maybe Format -> Inline -> [Inline]
index (Just (Format f)) c@(Code _ s) =
  case parse parseIndex "" s of
        Left _ -> [c]
        Right (term, subterm) ->
          case f of
            "html" -> [rawHtml term subterm]
            "latex" -> [rawLaTeX term subterm]
            _ -> []
index _ x = [x]


rawHtml :: String -> String -> Inline
rawHtml term subterm = RawInline (Format "html") ("<span id=" ++ term ++ ":" ++ subterm ++" class=\"index\"></a>")

rawLaTeX :: String -> String -> Inline
rawLaTeX term subterm = RawInline (Format "latex") ("\\index{"++term++"!"++subterm ++ "}")


parseIndex :: Parsec String () (String, String)
parseIndex = do
  string "(#"
  term <- spaces *> many1 (noneOf " ,") <* spaces
  char ','
  subterm <- spaces *> many1 (noneOf " )") <* spaces
  char ')'
  return (term,subterm)