pandoc/src/Text/Pandoc/Lua.hs
Albert Krewinkel b5bd8a9461
Lua: register script name in global variable
The name of the Lua script which is executed is made available in the
global Lua variable `PANDOC_SCRIPT_FILE`, both for Lua filters and
custom writers.

Closes: #4393
2018-02-24 22:43:28 +01:00

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{-
Copyright © 20172018 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 © 20172018 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 Control.Monad ((>=>))
import Foreign.Lua (FromLuaStack (peek), Lua, LuaException (..),
Status (OK), ToLuaStack (push))
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 /= OK
then do
luaErrMsg <- popValue
Lua.throwLuaError luaErrMsg
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 peek (-1)
else Lua.getglobal "_G" *> fmap (:[]) popValue
runAll luaFilters pd
where
registerFormat = do
push format
Lua.setglobal "FORMAT"
registerReaderOptions = do
push ropts
Lua.setglobal "PANDOC_READER_OPTIONS"
runAll :: [LuaFilter] -> Pandoc -> Lua Pandoc
runAll = foldr ((>=>) . walkMWithLuaFilter) return