Lua: use `Reader` type for custom readers.

3 files changed, 17 insertions, 25 deletions

diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Reader.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Reader.hs
index 6303dace3..44781c9fb 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Reader.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Reader.hs
@@ -13,40 +13,39 @@ Supports custom parsers written in Lua which produce a Pandoc AST.
 -}
 module Text.Pandoc.Lua.Reader ( readCustom ) where
 import Control.Exception
-import Control.Monad (when)
+import Control.Monad ((<=<), when)
 import Control.Monad.IO.Class (MonadIO)
 import Data.Maybe (fromMaybe)
 import HsLua as Lua hiding (Operation (Div))
-import Text.Pandoc.Definition
+import HsLua.Core.Run (newGCManagedState, withGCManagedState)
 import Text.Pandoc.Class (PandocMonad, findFileWithDataFallback, report)
 import Text.Pandoc.Logging
 import Text.Pandoc.Lua.Global (Global (..), setGlobals)
-import Text.Pandoc.Lua.Init (runLua)
+import Text.Pandoc.Lua.Init (runLuaWith)
 import Text.Pandoc.Lua.PandocLua
 import Text.Pandoc.Lua.Marshal.Pandoc (peekPandoc)
-import Text.Pandoc.Options
+import Text.Pandoc.Readers (Reader (..))
 import Text.Pandoc.Sources (ToSources(..), sourcesToText)
 import qualified Data.Text as T
 
 -- | Convert custom markup to Pandoc.
-readCustom :: (PandocMonad m, MonadIO m, ToSources s)
-            => FilePath -> ReaderOptions -> s -> m Pandoc
-readCustom luaFile opts srcs = do
-  let globals = [ PANDOC_SCRIPT_FILE luaFile ]
+readCustom :: (PandocMonad m, MonadIO m)
+            => FilePath -> m (Reader m)
+readCustom luaFile = do
+  luaState <- liftIO newGCManagedState
   luaFile' <- fromMaybe luaFile <$> findFileWithDataFallback "readers" luaFile
-  res <- runLua $ do
+  either throw pure <=< runLuaWith luaState $ do
+    let globals = [ PANDOC_SCRIPT_FILE luaFile ]
     setGlobals globals
     stat <- dofileTrace luaFile'
     -- check for error in lua script (later we'll change the return type
     -- to handle this more gracefully):
     when (stat /= Lua.OK)
       Lua.throwErrorAsException
-    parseCustom
-  case res of
-    Left msg -> throw msg
-    Right doc -> return doc
+    pure (reader luaState)
+
  where
-  parseCustom = do
+  reader st = TextReader $ \opts srcs -> liftIO . withGCManagedState st $ do
     let input = toSources srcs
     getglobal "Reader"
     push input
diff --git a/src/Text/Pandoc/App.hs b/src/Text/Pandoc/App.hs
index 49fe34172..b4a9454e5 100644
--- a/src/Text/Pandoc/App.hs
+++ b/src/Text/Pandoc/App.hs
@@ -64,7 +64,6 @@ import Text.Pandoc.Scripting (ScriptingEngine (..))
 import Text.Pandoc.SelfContained (makeSelfContained)
 import Text.Pandoc.Shared (eastAsianLineBreakFilter,
          headerShift, isURI, filterIpynbOutput, defaultUserDataDir, tshow)
-import Text.Pandoc.Sources (toSources)
 import Text.Pandoc.Writers.Shared (lookupMetaString)
 import Text.Pandoc.Readers.Markdown (yamlToMeta)
 import qualified Text.Pandoc.UTF8 as UTF8
@@ -166,13 +165,7 @@ convertWithOpts' scriptingEngine istty datadir opts = do
 
   (reader, readerExts) <-
     if ".lua" `T.isSuffixOf` readerName
-       then return ( TextReader $ \ropts s ->
-                       engineReadCustom scriptingEngine
-                                        (T.unpack readerName)
-                                        ropts
-                                        (toSources s)
-                   , mempty
-                   )
+       then (,mempty) <$> engineReadCustom scriptingEngine (T.unpack readerName)
        else if optSandbox opts
                then case runPure (getReader flvrd) of
                       Left e -> throwError e
diff --git a/src/Text/Pandoc/Scripting.hs b/src/Text/Pandoc/Scripting.hs
index 17bc2f972..9df00a5cf 100644
--- a/src/Text/Pandoc/Scripting.hs
+++ b/src/Text/Pandoc/Scripting.hs
@@ -22,7 +22,7 @@ import Text.Pandoc.Definition (Pandoc)
 import Text.Pandoc.Class.PandocMonad (PandocMonad)
 import Text.Pandoc.Error (PandocError (PandocNoScriptingEngine))
 import Text.Pandoc.Filter.Environment (Environment)
-import Text.Pandoc.Options (ReaderOptions)
+import Text.Pandoc.Readers (Reader)
 import Text.Pandoc.Sources (Sources)
 import Text.Pandoc.Writers (Writer)
 
@@ -36,7 +36,7 @@ data ScriptingEngine = ScriptingEngine
     -- ^ Use the scripting engine to run a filter.
 
   , engineReadCustom :: forall m. (PandocMonad m, MonadIO m)
-                     => FilePath -> ReaderOptions -> Sources -> m Pandoc
+                     => FilePath -> m (Reader m)
     -- ^ Function to parse input into a 'Pandoc' document.
 
   , engineWriteCustom :: forall m. (PandocMonad m, MonadIO m)
@@ -49,7 +49,7 @@ noEngine = ScriptingEngine
   { engineName = "none"
   , engineApplyFilter = \_env _args _fp _doc ->
       throwError PandocNoScriptingEngine
-  , engineReadCustom = \_fp _ropts _sources ->
+  , engineReadCustom = \_fp ->
       throwError PandocNoScriptingEngine
   , engineWriteCustom = \_fp ->
       throwError PandocNoScriptingEngine