Lua: use package pandoc-lua-marshal (#7719)

The marshaling functions for pandoc's AST are extracted into a separate
package. The package comes with a number of changes:

  - Pandoc's List module was rewritten in C, thereby improving error
    messages.

  - Lists of `Block` and `Inline` elements are marshaled using the new
    list types `Blocks` and `Inlines`, respectively. These types
    currently behave identical to the generic List type, but give better
    error messages. This also opens up the possibility of adding
    element-specific methods to these lists in the future.

  - Elements of type `MetaValue` are no longer pushed as values which
    have `.t` and `.tag` properties. This was already true for
    `MetaString` and `MetaBool` values, which are still marshaled as Lua
    strings and booleans, respectively. Affected values:

      + `MetaBlocks` values are marshaled as a `Blocks` list;

      + `MetaInlines` values are marshaled as a `Inlines` list;

      + `MetaList` values are marshaled as a generic pandoc `List`s.

      + `MetaMap` values are marshaled as plain tables and no longer
        given any metatable.

  - The test suite for marshaled objects and their constructors has
    been extended and improved.

  - A bug in Citation objects, where setting a citation's suffix
    modified it's prefix, has been fixed.

1 files changed, 3 insertions, 22 deletions

diff --git a/src/Text/Pandoc/Lua/PandocLua.hs b/src/Text/Pandoc/Lua/PandocLua.hs
index 6c2ebc622..71fdf8d5c 100644
--- a/src/Text/Pandoc/Lua/PandocLua.hs
+++ b/src/Text/Pandoc/Lua/PandocLua.hs
@@ -22,20 +22,18 @@ module Text.Pandoc.Lua.PandocLua
   ( PandocLua (..)
   , runPandocLua
   , liftPandocLua
-  , loadDefaultModule
   ) where
 
 import Control.Monad.Catch (MonadCatch, MonadMask, MonadThrow)
 import Control.Monad.Except (MonadError (catchError, throwError))
 import Control.Monad.IO.Class (MonadIO)
 import HsLua as Lua
-import Text.Pandoc.Class.PandocMonad (PandocMonad (..), readDefaultDataFile)
-import Text.Pandoc.Error (PandocError (PandocLuaError))
+import Text.Pandoc.Class.PandocMonad (PandocMonad (..))
+import Text.Pandoc.Error (PandocError)
 import Text.Pandoc.Lua.Global (Global (..), setGlobals)
-import Text.Pandoc.Lua.Marshaling.CommonState (peekCommonState)
+import Text.Pandoc.Lua.Marshal.CommonState (peekCommonState)
 
 import qualified Control.Monad.Catch as Catch
-import qualified Data.Text as T
 import qualified Text.Pandoc.Class.IO as IO
 
 -- | Type providing access to both, pandoc and Lua operations.
@@ -75,23 +73,6 @@ instance {-# OVERLAPPING #-} Exposable PandocError (PandocLua NumResults) where
 instance Pushable a => Exposable PandocError (PandocLua a) where
   partialApply _narg x = 1 <$ (unPandocLua x >>= Lua.push)
 
--- | Load a pure Lua module included with pandoc. Leaves the result on
--- the stack and returns @NumResults 1@.
---
--- The script is loaded from the default data directory. We do not load
--- from data directories supplied via command line, as this could cause
--- scripts to be executed even though they had not been passed explicitly.
-loadDefaultModule :: String -> PandocLua NumResults
-loadDefaultModule name = do
-  script <- readDefaultDataFile (name <> ".lua")
-  result <- liftPandocLua $ Lua.dostring script
-  if result == Lua.OK
-    then return (1 :: NumResults)
-    else do
-      msg <- liftPandocLua Lua.popValue
-      let err = "Error while loading `" <> name <> "`.\n" <> msg
-      throwError $ PandocLuaError (T.pack err)
-
 -- | Global variables which should always be set.
 defaultGlobals :: PandocMonad m => m [Global]
 defaultGlobals = do