1 files changed, 12 insertions, 3 deletions
diff --git a/src/Text/Pandoc/Filter.hs b/src/Text/Pandoc/Filter.hs
index 502aaefae..f5c1a4f76 100644
--- a/src/Text/Pandoc/Filter.hs
+++ b/src/Text/Pandoc/Filter.hs
@@ -26,6 +26,7 @@ import Text.Pandoc.Class.PandocMonad (report, getVerbosity)
 import Text.Pandoc.Definition (Pandoc)
 import Text.Pandoc.Options (ReaderOptions)
 import Text.Pandoc.Logging
+import Text.Pandoc.Citeproc (processCitations)
 import qualified Text.Pandoc.Filter.JSON as JSONFilter
 import qualified Text.Pandoc.Filter.Lua as LuaFilter
 import qualified Text.Pandoc.Filter.Path as Path
@@ -39,6 +40,7 @@ import Control.Monad (foldM, when)
 -- | Type of filter and path to filter file.
 data Filter = LuaFilter FilePath
             | JSONFilter FilePath
+            | CiteprocFilter -- built-in citeproc
             deriving (Show, Generic)
 
 instance FromYAML Filter where
@@ -47,15 +49,19 @@ instance FromYAML Filter where
     ty <- m .: "type"
     fp <- m .: "path"
     case ty of
+      "citeproc" -> return CiteprocFilter
       "lua"  -> return $ LuaFilter $ T.unpack fp
       "json" -> return $ JSONFilter $ T.unpack fp
       _      -> fail $ "Unknown filter type " ++ show (ty :: T.Text)) node
   <|>
   (withStr "Filter" $ \t -> do
     let fp = T.unpack t
-    case takeExtension fp of
-      ".lua"  -> return $ LuaFilter fp
-      _       -> return $ JSONFilter fp) node
+    if fp == "citeproc"
+       then return CiteprocFilter
+       else return $
+         case takeExtension fp of
+           ".lua"  -> LuaFilter fp
+           _       -> JSONFilter fp) node
 
 -- | Modify the given document using a filter.
 applyFilters :: ReaderOptions
@@ -71,6 +77,8 @@ applyFilters ropts filters args d = do
     withMessages f $ JSONFilter.apply ropts args f doc
   applyFilter doc (LuaFilter f)  =
     withMessages f $ LuaFilter.apply ropts args f doc
+  applyFilter doc CiteprocFilter =
+    processCitations doc
   withMessages f action = do
     verbosity <- getVerbosity
     when (verbosity == INFO) $ report $ RunningFilter f
@@ -85,5 +93,6 @@ applyFilters ropts filters args d = do
 expandFilterPath :: Filter -> PandocIO Filter
 expandFilterPath (LuaFilter fp) = LuaFilter <$> Path.expandFilterPath fp
 expandFilterPath (JSONFilter fp) = JSONFilter <$> Path.expandFilterPath fp
+expandFilterPath CiteprocFilter = return CiteprocFilter
 
 $(deriveJSON defaultOptions ''Filter)