1 files changed, 23 insertions, 2 deletions
diff --git a/src/Text/Pandoc/Lua/Module/Utils.hs b/src/Text/Pandoc/Lua/Module/Utils.hs
index 3a3727355..35495dae1 100644
--- a/src/Text/Pandoc/Lua/Module/Utils.hs
+++ b/src/Text/Pandoc/Lua/Module/Utils.hs
@@ -30,10 +30,10 @@ module Text.Pandoc.Lua.Module.Utils
   ) where
 
 import Control.Applicative ((<|>))
-import Foreign.Lua (FromLuaStack, Lua, NumResults)
+import Foreign.Lua (FromLuaStack, Lua, LuaInteger, NumResults)
 import Text.Pandoc.Definition (Pandoc, Meta, Block, Inline)
 import Text.Pandoc.Lua.StackInstances ()
-import Text.Pandoc.Lua.Util (addFunction)
+import Text.Pandoc.Lua.Util (OrNil (OrNil), addFunction)
 
 import qualified Data.Digest.Pure.SHA as SHA
 import qualified Data.ByteString.Lazy as BSL
@@ -44,15 +44,32 @@ import qualified Text.Pandoc.Shared as Shared
 pushModule :: Lua NumResults
 pushModule = do
   Lua.newtable
+  addFunction "hierarchicalize" hierarchicalize
+  addFunction "normalize_date" normalizeDate
   addFunction "sha1" sha1
   addFunction "stringify" stringify
+  addFunction "to_roman_numeral" toRomanNumeral
   return 1
 
+-- | Convert list of Pandoc blocks into (hierarchical) list of Elements.
+hierarchicalize :: [Block] -> Lua [Shared.Element]
+hierarchicalize = return . Shared.hierarchicalize
+
+-- | Parse a date and convert (if possible) to "YYYY-MM-DD" format. We
+-- limit years to the range 1601-9999 (ISO 8601 accepts greater than
+-- or equal to 1583, but MS Word only accepts dates starting 1601).
+-- Returns nil instead of a string if the conversion failed.
+normalizeDate :: String -> Lua (OrNil String)
+normalizeDate = return . OrNil . Shared.normalizeDate
+
 -- | Calculate the hash of the given contents.
 sha1 :: BSL.ByteString
      -> Lua String
 sha1 = return . SHA.showDigest . SHA.sha1
 
+-- | Convert pandoc structure to a string with formatting removed.
+-- Footnotes are skipped (since we don't want their contents in link
+-- labels).
 stringify :: AstElement -> Lua String
 stringify el = return $ case el of
   PandocElement pd -> Shared.stringify pd
@@ -77,3 +94,7 @@ instance FromLuaStack AstElement where
       Right x -> return x
       Left _ -> Lua.throwLuaError
         "Expected an AST element, but could not parse value as such."
+
+-- | Convert a number < 4000 to uppercase roman numeral.
+toRomanNumeral :: LuaInteger -> Lua String
+toRomanNumeral = return . Shared.toRomanNumeral . fromIntegral