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

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typeable/pandoc/src/Text/Pandoc/Lua.hs

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1{-# LANGUAGE NoImplicitPrelude #-}

2{-

5This program is free software; you can redistribute it and/or modify

6it under the terms of the GNU General Public License as published by

7the Free Software Foundation; either version 2 of the License, or

8(at your option) any later version.

10This program is distributed in the hope that it will be useful,

11but WITHOUT ANY WARRANTY; without even the implied warranty of

12MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the

13GNU General Public License for more details.

15You should have received a copy of the GNU General Public License

16along with this program; if not, write to the Free Software

17Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

18-}

19{- |

20 Module : Text.Pandoc.Lua

22 License : GNU GPL, version 2 or above

24 Maintainer : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>

25 Stability : alpha

27Running pandoc Lua filters.

28-}

29module Text.Pandoc.Lua

30 ( LuaException (..)

31 , runLuaFilter

32 , runPandocLua

33 ) where

35import Prelude

36import Control.Monad ((>=>))

37import Foreign.Lua (FromLuaStack (peek), Lua, LuaException (..),

38 Status (OK), ToLuaStack (push))

39import Text.Pandoc.Class (PandocIO)

40import Text.Pandoc.Definition (Pandoc)

41import Text.Pandoc.Lua.Filter (LuaFilter, walkMWithLuaFilter)

42import Text.Pandoc.Lua.Init (runPandocLua, registerScriptPath)

43import Text.Pandoc.Lua.Util (popValue)

44import Text.Pandoc.Options (ReaderOptions)

45import qualified Foreign.Lua as Lua

47-- | Run the Lua filter in @filterPath@ for a transformation to target

48-- format @format@. Pandoc uses Lua init files to setup the Lua

49-- interpreter.

50runLuaFilter :: ReaderOptions -> FilePath -> String

51 -> Pandoc -> PandocIO (Either LuaException Pandoc)

52runLuaFilter ropts filterPath format doc =

53 runPandocLua (runLuaFilter' ropts filterPath format doc)

55runLuaFilter' :: ReaderOptions -> FilePath -> String

56 -> Pandoc -> Lua Pandoc

57runLuaFilter' ropts filterPath format pd = do

58 registerFormat

59 registerReaderOptions

60 registerScriptPath filterPath

61 top <- Lua.gettop

62 stat <- Lua.dofile filterPath

63 if stat /= OK

64 then do

65 luaErrMsg <- popValue

66 Lua.throwLuaError luaErrMsg

67 else do

68 newtop <- Lua.gettop

69 -- Use the returned filters, or the implicitly defined global filter if

70 -- nothing was returned.

71 luaFilters <- if newtop - top >= 1

72 then peek (-1)

73 else Lua.getglobal "_G" *> fmap (:[]) popValue

74 runAll luaFilters pd

75 where

76 registerFormat = do

77 push format

78 Lua.setglobal "FORMAT"

80 registerReaderOptions = do

81 push ropts

82 Lua.setglobal "PANDOC_READER_OPTIONS"

84runAll :: [LuaFilter] -> Pandoc -> Lua Pandoc

85runAll = foldr ((>=>) . walkMWithLuaFilter) return