Lua modules: added pandoc.utils module

A new module `pandoc.utils` has been created. It holds utility functions
like `sha1`, which was moved from the main `pandoc` module.

6 files changed, 79 insertions, 22 deletions

diff --git a/data/pandoc.lua b/data/pandoc.lua
index df8aa06c4..98d274cf4 100644
--- a/data/pandoc.lua
+++ b/data/pandoc.lua
@@ -903,4 +903,9 @@ function M.global_filter()
   return res
 end
 
+------------------------------------------------------------------------
+-- Functions which have moved to different modules
+local utils = require 'pandoc.utils'
+M.sha1 = utils.sha1
+
 return M
diff --git a/doc/lua-filters.md b/doc/lua-filters.md
index 9beeda185..a109871f6 100644
--- a/doc/lua-filters.md
+++ b/doc/lua-filters.md
@@ -1405,18 +1405,6 @@ Lua functions for pandoc scripts.
         -- the above is equivallent to
         -- return {{Str = Str}}
 
-[`sha1 (contents)`]{#mediabag-sha1}
-
-:   Returns the SHA1 has of the contents.
-
-    Returns:
-
-    -   SHA1 hash of the contents.
-
-    Usage:
-
-        local fp = pandoc.mediabag.sha1("foobar")
-
 [`pipe (command, args, input)`]{#mediabag-sha1}
 
 :   Runs command with arguments, passing it some input,
@@ -1436,9 +1424,28 @@ Lua functions for pandoc scripts.
 
         local output = pandoc.pipe("sed", {"-e","s/a/b/"}, "abc")
 
-# Submodule mediabag
 
-The submodule `mediabag` allows accessing pandoc's media
+# Module pandoc.utils
+
+This module exposes internal pandoc functions and utility
+functions.
+
+[`sha1 (contents)`]{#utils-sha1}
+
+:   Returns the SHA1 has of the contents.
+
+    Returns:
+
+    -   SHA1 hash of the contents.
+
+    Usage:
+
+        local fp = pandoc.utils.sha1("foobar")
+
+
+# Module pandoc.mediabag
+
+The `pandoc.mediabag` module allows accessing pandoc's media
 storage. The "media bag" is used when pandoc is called with the
 `--extract-media` or `--standalone`/`-s` option.
 
diff --git a/pandoc.cabal b/pandoc.cabal
index 0b9e46f29..557c9a626 100644
--- a/pandoc.cabal
+++ b/pandoc.cabal
@@ -525,6 +525,7 @@ library
                    Text.Pandoc.Lua.Init,
                    Text.Pandoc.Lua.Module.MediaBag,
                    Text.Pandoc.Lua.Module.Pandoc,
+                   Text.Pandoc.Lua.Module.Utils,
                    Text.Pandoc.Lua.Packages,
                    Text.Pandoc.Lua.StackInstances,
                    Text.Pandoc.Lua.Util,
diff --git a/src/Text/Pandoc/Lua/Module/Pandoc.hs b/src/Text/Pandoc/Lua/Module/Pandoc.hs
index ed80b9715..5b8714e07 100644
--- a/src/Text/Pandoc/Lua/Module/Pandoc.hs
+++ b/src/Text/Pandoc/Lua/Module/Pandoc.hs
@@ -32,7 +32,6 @@ module Text.Pandoc.Lua.Module.Pandoc
 
 import Control.Monad (when)
 import Data.Default (Default (..))
-import Data.Digest.Pure.SHA (sha1, showDigest)
 import Data.Maybe (fromMaybe)
 import Data.Text (pack)
 import Foreign.Lua (ToLuaStack, FromLuaStack, Lua, NumResults, liftIO)
@@ -59,7 +58,6 @@ pushModule datadir = do
   loadScriptFromDataDir datadir "pandoc.lua"
   addFunction "read" readDoc
   addFunction "pipe" pipeFn
-  addFunction "sha1" sha1HashFn
   addFunction "walk_block" walkBlock
   addFunction "walk_inline" walkInline
   return 1
@@ -88,12 +86,6 @@ readDoc content formatSpecOrNil = do
             Left s   -> raiseError (show s)              -- error while reading
         _  -> raiseError "Only string formats are supported at the moment."
 
-sha1HashFn :: BL.ByteString
-           -> Lua NumResults
-sha1HashFn contents = do
-  Lua.push $ showDigest (sha1 contents)
-  return 1
-
 -- | Pipes input through a command.
 pipeFn :: String
        -> [String]
diff --git a/src/Text/Pandoc/Lua/Module/Utils.hs b/src/Text/Pandoc/Lua/Module/Utils.hs
new file mode 100644
index 000000000..496fdbc0a
--- /dev/null
+++ b/src/Text/Pandoc/Lua/Module/Utils.hs
@@ -0,0 +1,50 @@
+{-
+Copyright © 2017 Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>
+
+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
+-}
+{- |
+   Module      : Text.Pandoc.Lua.Module.Utils
+   Copyright   : Copyright © 2017 Albert Krewinkel
+   License     : GNU GPL, version 2 or above
+
+   Maintainer  : Albert Krewinkel <tarleb+pandoc@moltkeplatz.de>
+   Stability   : alpha
+
+Utility module for lua, exposing internal helper functions.
+-}
+module Text.Pandoc.Lua.Module.Utils
+  ( pushModule
+  ) where
+
+import Data.Digest.Pure.SHA (sha1, showDigest)
+import Foreign.Lua (Lua, NumResults)
+import Text.Pandoc.Lua.StackInstances ()
+import Text.Pandoc.Lua.Util (addFunction)
+
+import qualified Data.ByteString.Lazy as BSL
+import qualified Foreign.Lua as Lua
+
+-- | Push the "pandoc.utils" module to the lua stack.
+pushModule :: Lua NumResults
+pushModule = do
+  Lua.newtable
+  addFunction "sha1" sha1HashFn
+  return 1
+
+-- | Calculate the hash of the given contents.
+sha1HashFn :: BSL.ByteString
+           -> Lua String
+sha1HashFn = return . showDigest . sha1
diff --git a/src/Text/Pandoc/Lua/Packages.hs b/src/Text/Pandoc/Lua/Packages.hs
index 03847c979..f26c17084 100644
--- a/src/Text/Pandoc/Lua/Packages.hs
+++ b/src/Text/Pandoc/Lua/Packages.hs
@@ -43,6 +43,7 @@ import Text.Pandoc.Lua.Util (dostring')
 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.Utils as Utils
 
 -- | Parameters used to create lua packages/modules.
 data LuaPackageParams = LuaPackageParams
@@ -77,6 +78,7 @@ pandocPackageSearcher luaPkgParams pkgName =
     "pandoc.mediabag" -> let st    = luaPkgCommonState luaPkgParams
                              mbRef = luaPkgMediaBag luaPkgParams
                          in pushWrappedHsFun (MediaBag.pushModule st mbRef)
+    "pandoc.utils"    -> pushWrappedHsFun Utils.pushModule
     _ -> searchPureLuaLoader
  where
   pushWrappedHsFun f = do