{-# LANGUAGE FlexibleContexts #-} {-# LANGUAGE NoImplicitPrelude #-} {-# LANGUAGE ScopedTypeVariables #-} {- | Module : Text.Pandoc.Lua.Packages Copyright : Copyright © 2017-2019 Albert Krewinkel License : GNU GPL, version 2 or above Maintainer : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de> Stability : alpha Pandoc module for lua. -} module Text.Pandoc.Lua.Packages ( LuaPackageParams (..) , installPandocPackageSearcher ) where import Prelude import Control.Monad (forM_) import Data.ByteString (ByteString) import Foreign.Lua (Lua, NumResults, liftIO) import Text.Pandoc.Class (readDataFile, runIO, setUserDataDir) import qualified Foreign.Lua as Lua import Text.Pandoc.Lua.Module.Pandoc as Pandoc import Text.Pandoc.Lua.Module.MediaBag as MediaBag import Text.Pandoc.Lua.Module.System as System import Text.Pandoc.Lua.Module.Types as Types import Text.Pandoc.Lua.Module.Utils as Utils -- | Parameters used to create lua packages/modules. data LuaPackageParams = LuaPackageParams { luaPkgDataDir :: Maybe FilePath } -- | Insert pandoc's package loader as the first loader, making it the default. installPandocPackageSearcher :: LuaPackageParams -> Lua () installPandocPackageSearcher luaPkgParams = do Lua.getglobal' "package.searchers" shiftArray Lua.pushHaskellFunction (pandocPackageSearcher luaPkgParams) Lua.rawseti (Lua.nthFromTop 2) 1 Lua.pop 1 -- remove 'package.searchers' from stack where shiftArray = forM_ [4, 3, 2, 1] $ \i -> do Lua.rawgeti (-1) i Lua.rawseti (-2) (i + 1) -- | Load a pandoc module. pandocPackageSearcher :: LuaPackageParams -> String -> Lua NumResults pandocPackageSearcher pkgParams pkgName = case pkgName of "pandoc" -> let datadir = luaPkgDataDir pkgParams in pushWrappedHsFun (Pandoc.pushModule datadir) "pandoc.mediabag" -> pushWrappedHsFun MediaBag.pushModule "pandoc.system" -> pushWrappedHsFun System.pushModule "pandoc.types" -> pushWrappedHsFun Types.pushModule "pandoc.utils" -> let datadir = luaPkgDataDir pkgParams in pushWrappedHsFun (Utils.pushModule datadir) _ -> searchPureLuaLoader where pushWrappedHsFun f = do Lua.pushHaskellFunction f return 1 searchPureLuaLoader = do let filename = pkgName ++ ".lua" modScript <- liftIO (dataDirScript (luaPkgDataDir pkgParams) filename) case modScript of Just script -> pushWrappedHsFun (loadStringAsPackage pkgName script) Nothing -> do Lua.push ("\n\tno file '" ++ filename ++ "' in pandoc's datadir") return 1 loadStringAsPackage :: String -> ByteString -> Lua NumResults loadStringAsPackage pkgName script = do status <- Lua.dostring script if status == Lua.OK then return (1 :: NumResults) else do msg <- Lua.popValue Lua.raiseError ("Error while loading `" <> pkgName <> "`.\n" <> msg) -- | Get the ByteString representation of the pandoc module. dataDirScript :: Maybe FilePath -> FilePath -> IO (Maybe ByteString) dataDirScript datadir moduleFile = do res <- runIO $ setUserDataDir datadir >> readDataFile moduleFile return $ case res of Left _ -> Nothing Right s -> Just s