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diff --git a/src/Text/Pandoc/Filter.hs b/src/Text/Pandoc/Filter.hs
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+++ b/src/Text/Pandoc/Filter.hs
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+{-
+Copyright (C) 2006-2017 John MacFarlane <jgm@berkeley.edu>
+
+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
+-}
+{-# LANGUAGE TemplateHaskell     #-}
+
+{- |
+   Module      : Text.Pandoc.Filter
+   Copyright   : Copyright (C) 2006-2017 John MacFarlane
+   License     : GNU GPL, version 2 or above
+
+   Maintainer  : John MacFarlane <jgm@berkeley@edu>
+   Stability   : alpha
+   Portability : portable
+
+Programmatically modifications of pandoc documents.
+-}
+module Text.Pandoc.Filter
+  ( Filter (..)
+  , applyFilters
+  ) where
+
+import Data.Aeson (defaultOptions)
+import Data.Aeson.TH (deriveJSON)
+import Data.Foldable (foldrM)
+import Text.Pandoc.Class (PandocIO)
+import Text.Pandoc.Definition (Pandoc)
+import Text.Pandoc.Options (ReaderOptions)
+import qualified Text.Pandoc.Filter.JSON as JSONFilter
+import qualified Text.Pandoc.Filter.Lua as LuaFilter
+
+data Filter = LuaFilter FilePath
+            | JSONFilter FilePath
+            deriving (Show)
+
+applyFilters :: ReaderOptions
+             -> [Filter]
+             -> [String]
+             -> Pandoc
+             -> PandocIO Pandoc
+applyFilters ropts filters args d =
+  foldrM ($) d $ map applyFilter filters
+ where
+  applyFilter (JSONFilter f) = JSONFilter.apply ropts args f
+  applyFilter (LuaFilter f)  = LuaFilter.apply ropts args f
+
+$(deriveJSON defaultOptions ''Filter)