{-# LANGUAGE NoImplicitPrelude #-} {- Copyright © 2017–2018 Albert Krewinkel <tarleb+pandoc@moltkeplatz.de> This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA -} {- | Module : Text.Pandoc.Lua Copyright : Copyright © 2017–2018 Albert Krewinkel License : GNU GPL, version 2 or above Maintainer : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de> Stability : alpha Running pandoc Lua filters. -} module Text.Pandoc.Lua ( LuaException (..) , runLuaFilter , runPandocLua ) where import Prelude import Control.Monad ((>=>)) import Foreign.Lua (Lua, LuaException (..)) import Text.Pandoc.Class (PandocIO) import Text.Pandoc.Definition (Pandoc) import Text.Pandoc.Lua.Filter (LuaFilter, walkMWithLuaFilter) import Text.Pandoc.Lua.Init (runPandocLua, registerScriptPath) import Text.Pandoc.Lua.Util (popValue) import Text.Pandoc.Options (ReaderOptions) import qualified Foreign.Lua as Lua -- | Run the Lua filter in @filterPath@ for a transformation to target -- format @format@. Pandoc uses Lua init files to setup the Lua -- interpreter. runLuaFilter :: ReaderOptions -> FilePath -> String -> Pandoc -> PandocIO (Either LuaException Pandoc) runLuaFilter ropts filterPath format doc = runPandocLua (runLuaFilter' ropts filterPath format doc) runLuaFilter' :: ReaderOptions -> FilePath -> String -> Pandoc -> Lua Pandoc runLuaFilter' ropts filterPath format pd = do registerFormat registerReaderOptions registerScriptPath filterPath top <- Lua.gettop stat <- Lua.dofile filterPath if stat /= Lua.OK then Lua.throwTopMessageAsError else do newtop <- Lua.gettop -- Use the returned filters, or the implicitly defined global filter if -- nothing was returned. luaFilters <- if newtop - top >= 1 then Lua.peek Lua.stackTop else Lua.getglobal "_G" *> fmap (:[]) popValue runAll luaFilters pd where registerFormat = do Lua.push format Lua.setglobal "FORMAT" registerReaderOptions = do Lua.push ropts Lua.setglobal "PANDOC_READER_OPTIONS" runAll :: [LuaFilter] -> Pandoc -> Lua Pandoc runAll = foldr ((>=>) . walkMWithLuaFilter) return