Lua: cleanup module dependencies

Ensures a cleaner module dependency graph.

10 files changed, 61 insertions, 93 deletions

diff --git a/pandoc-lua-engine/pandoc-lua-engine.cabal b/pandoc-lua-engine/pandoc-lua-engine.cabal
index 623ba1363..b8f3abbd1 100644
--- a/pandoc-lua-engine/pandoc-lua-engine.cabal
+++ b/pandoc-lua-engine/pandoc-lua-engine.cabal
@@ -60,8 +60,7 @@ library
   import:              common-options
   hs-source-dirs:      src
   exposed-modules:     Text.Pandoc.Lua
-  other-modules:       Text.Pandoc.Lua.ErrorConversion
-                     , Text.Pandoc.Lua.Filter
+  other-modules:       Text.Pandoc.Lua.Filter
                      , Text.Pandoc.Lua.Global
                      , Text.Pandoc.Lua.Init
                      , Text.Pandoc.Lua.Marshal.CommonState
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/ErrorConversion.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/ErrorConversion.hs
deleted file mode 100644
index 3968eba84..000000000
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/ErrorConversion.hs
+++ /dev/null
@@ -1,40 +0,0 @@
-{-# OPTIONS_GHC -fno-warn-orphans #-}
-{- |
-   Module      : Text.Pandoc.Lua.ErrorConversion
-   Copyright   : © 2020-2022 Albert Krewinkel
-   License     : GNU GPL, version 2 or above
-
-   Maintainer  : Albert Krewinkel <[email protected]>
-   Stability   : alpha
-
-Define how Lua errors are converted into @'PandocError'@ Haskell
-exceptions, and /vice versa/.
--}
-module Text.Pandoc.Lua.ErrorConversion
-  ( addContextToException
-  ) where
-
-import HsLua (LuaError, LuaE, resultToEither, runPeek, top)
-import Text.Pandoc.Error (PandocError (PandocLuaError))
-import Text.Pandoc.Lua.Marshal.PandocError (pushPandocError, peekPandocError)
-
-import qualified Data.Text as T
-import qualified HsLua as Lua
-
-addContextToException :: ()
-addContextToException = undefined
-
--- | Retrieve a @'PandocError'@ from the Lua stack.
-popPandocError :: LuaE PandocError PandocError
-popPandocError = do
-  errResult <- runPeek $ peekPandocError top
-  case resultToEither errResult of
-    Right x -> return x
-    Left err -> return $ PandocLuaError (T.pack err)
-
--- Ensure conversions between Lua errors and 'PandocError' exceptions
--- are possible.
-instance LuaError PandocError where
-  popException = popPandocError
-  pushException = pushPandocError
-  luaException = PandocLuaError . T.pack
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Filter.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Filter.hs
index c019095f8..6e7dc0fba 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Filter.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Filter.hs
@@ -19,11 +19,11 @@ import Control.Monad ((>=>), (<$!>))
 import HsLua as Lua
 import Text.Pandoc.Definition
 import Text.Pandoc.Filter (Environment (..))
-import Text.Pandoc.Lua.ErrorConversion ()
 import Text.Pandoc.Lua.Marshal.AST
 import Text.Pandoc.Lua.Marshal.Filter
 import Text.Pandoc.Lua.Global (Global (..), setGlobals)
 import Text.Pandoc.Lua.Init (runLua)
+import Text.Pandoc.Lua.PandocLua ()
 import Control.Exception (throw)
 import qualified Data.Text as T
 import Text.Pandoc.Class (PandocMonad)
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Global.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Global.hs
index 702ba7bd5..5ec7ced64 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Global.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Global.hs
@@ -23,7 +23,7 @@ import Text.Pandoc.Lua.Marshal.CommonState (pushCommonState)
 import Text.Pandoc.Lua.Marshal.Pandoc (pushPandoc)
 import Text.Pandoc.Lua.Marshal.ReaderOptions (pushReaderOptionsReadonly)
 import Text.Pandoc.Lua.Marshal.WriterOptions (pushWriterOptions)
-import Text.Pandoc.Lua.Orphans ()
+import Text.Pandoc.Lua.PandocLua ()
 import Text.Pandoc.Options (ReaderOptions, WriterOptions)
 import Text.Pandoc.Shared (pandocVersion)
 
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Init.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Init.hs
index 98a2f5c7b..ffe77bfde 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Init.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Init.hs
@@ -1,5 +1,6 @@
 {-# LANGUAGE LambdaCase        #-}
 {-# LANGUAGE OverloadedStrings #-}
+{-# LANGUAGE RankNTypes        #-}
 {- |
    Module      : Text.Pandoc.Lua
    Copyright   : Copyright © 2017-2022 Albert Krewinkel
@@ -22,11 +23,12 @@ import Control.Monad.Trans (MonadIO (..))
 import Data.Maybe (catMaybes)
 import HsLua as Lua hiding (status, try)
 import HsLua.Core.Run as Lua
-import Text.Pandoc.Class (PandocMonad)
+import Text.Pandoc.Class (PandocMonad (..))
 import Text.Pandoc.Data (readDataFile)
 import Text.Pandoc.Error (PandocError (PandocLuaError))
+import Text.Pandoc.Lua.Global (Global (..), setGlobals)
 import Text.Pandoc.Lua.Marshal.List (newListMetatable, pushListModule)
-import Text.Pandoc.Lua.PandocLua (PandocLua, liftPandocLua, runPandocLuaWith)
+import Text.Pandoc.Lua.PandocLua (PandocLua (..), liftPandocLua)
 import qualified Data.ByteString.Char8 as Char8
 import qualified Data.Text as T
 import qualified Lua.LPeg as LPeg
@@ -177,3 +179,31 @@ initLuaState = do
 initJsonMetatable :: PandocLua ()
 initJsonMetatable = liftPandocLua $ do
   newListMetatable HsLua.Aeson.jsonarray (pure ())
+
+-- | Evaluate a @'PandocLua'@ computation, running all contained Lua
+-- operations.
+runPandocLuaWith :: (PandocMonad m, MonadIO m)
+                 => (forall b. LuaE PandocError b -> IO b)
+                 -> PandocLua a
+                 -> m a
+runPandocLuaWith runner pLua = do
+  origState <- getCommonState
+  globals <- defaultGlobals
+  (result, newState) <- liftIO . runner . unPandocLua $ do
+    putCommonState origState
+    liftPandocLua $ setGlobals globals
+    r <- pLua
+    c <- getCommonState
+    return (r, c)
+  putCommonState newState
+  return result
+
+-- | Global variables which should always be set.
+defaultGlobals :: PandocMonad m => m [Global]
+defaultGlobals = do
+  commonState <- getCommonState
+  return
+    [ PANDOC_API_VERSION
+    , PANDOC_STATE commonState
+    , PANDOC_VERSION
+    ]
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Format.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Format.hs
index 8fa0485fc..7eb66b3ca 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Format.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Format.hs
@@ -15,8 +15,8 @@ import HsLua
 import Text.Pandoc.Error (PandocError)
 import Text.Pandoc.Extensions
   ( getAllExtensions, getDefaultExtensions )
-import Text.Pandoc.Lua.ErrorConversion ()
 import Text.Pandoc.Lua.Marshal.Extensions (pushExtensions)
+import Text.Pandoc.Lua.PandocLua ()
 
 import qualified Data.Text as T
 
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Types.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Types.hs
index b8d45d93e..7d9ad6784 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Types.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Types.hs
@@ -17,7 +17,7 @@ import HsLua ( Module (..), (###), (<#>), (=#>)
              , defun, functionResult, parameter)
 import HsLua.Module.Version (peekVersionFuzzy, pushVersion)
 import Text.Pandoc.Error (PandocError)
-import Text.Pandoc.Lua.ErrorConversion ()
+import Text.Pandoc.Lua.PandocLua ()
 
 -- | Push the pandoc.types module on the Lua stack.
 documentedModule :: Module PandocError
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Utils.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Utils.hs
index 33349870c..16305b76e 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Utils.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Module/Utils.hs
@@ -204,7 +204,7 @@ stringify idx = forcePeek . retrieving "stringifyable element" $
 -- | Converts an old/simple table into a normal table block element.
 from_simple_table :: SimpleTable -> LuaE PandocError NumResults
 from_simple_table (SimpleTable capt aligns widths head' body) = do
-  Lua.push $ Table
+  pushBlock $ Table
     nullAttr
     (Caption Nothing [Plain capt | not (null capt)])
     (zipWith (\a w -> (a, toColWidth w)) aligns widths)
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/Orphans.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/Orphans.hs
index 62b54d051..db58349d2 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/Orphans.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/Orphans.hs
@@ -23,7 +23,6 @@ import Text.Pandoc.Lua.Marshal.Context ()
 import Text.Pandoc.Lua.Marshal.PandocError()
 import Text.Pandoc.Lua.Marshal.ReaderOptions ()
 import Text.Pandoc.Lua.Marshal.Sources (pushSources)
-import Text.Pandoc.Lua.ErrorConversion ()
 import Text.Pandoc.Sources (Sources)
 
 instance Pushable Pandoc where
diff --git a/pandoc-lua-engine/src/Text/Pandoc/Lua/PandocLua.hs b/pandoc-lua-engine/src/Text/Pandoc/Lua/PandocLua.hs
index 6564ec91d..d922dfe1c 100644
--- a/pandoc-lua-engine/src/Text/Pandoc/Lua/PandocLua.hs
+++ b/pandoc-lua-engine/src/Text/Pandoc/Lua/PandocLua.hs
@@ -4,24 +4,18 @@
 {-# LANGUAGE GeneralizedNewtypeDeriving #-}
 {-# LANGUAGE MultiParamTypeClasses #-}
 {-# LANGUAGE OverloadedStrings #-}
-{-# LANGUAGE RankNTypes #-}
-{-# LANGUAGE ScopedTypeVariables #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
 {- |
    Module      : Text.Pandoc.Lua.PandocLua
-   Copyright   : Copyright © 2020-2022 Albert Krewinkel
-   License     : GNU GPL, version 2 or above
-
+   Copyright   : © 2020-2022 Albert Krewinkel
+   License     : GPL-2.0-or-later
    Maintainer  : Albert Krewinkel <[email protected]>
-   Stability   : alpha
 
 PandocMonad instance which allows execution of Lua operations and which
 uses Lua to handle state.
 -}
 module Text.Pandoc.Lua.PandocLua
   ( PandocLua (..)
-  , runPandocLua
-  , runPandocLuaWith
   , liftPandocLua
   ) where
 
@@ -30,11 +24,12 @@ import Control.Monad.Except (MonadError (catchError, throwError))
 import Control.Monad.IO.Class (MonadIO)
 import HsLua as Lua
 import Text.Pandoc.Class (PandocMonad (..))
-import Text.Pandoc.Error (PandocError)
-import Text.Pandoc.Lua.Global (Global (..), setGlobals)
-import Text.Pandoc.Lua.Marshal.CommonState (peekCommonState)
+import Text.Pandoc.Error (PandocError (..))
+import Text.Pandoc.Lua.Marshal.CommonState (peekCommonState, pushCommonState)
+import Text.Pandoc.Lua.Marshal.PandocError (peekPandocError, pushPandocError)
 
 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.
@@ -53,43 +48,12 @@ newtype PandocLua a = PandocLua { unPandocLua :: LuaE PandocError a }
 liftPandocLua :: LuaE PandocError a -> PandocLua a
 liftPandocLua = PandocLua
 
--- | Evaluate a @'PandocLua'@ computation, running all contained Lua
--- operations..
-runPandocLua :: (PandocMonad m, MonadIO m) => PandocLua a -> m a
-runPandocLua = runPandocLuaWith Lua.run
-
-runPandocLuaWith :: (PandocMonad m, MonadIO m)
-                 => (forall b. LuaE PandocError b -> IO b)
-                 -> PandocLua a
-                 -> m a
-runPandocLuaWith runner pLua = do
-  origState <- getCommonState
-  globals <- defaultGlobals
-  (result, newState) <- liftIO . runner . unPandocLua $ do
-    putCommonState origState
-    liftPandocLua $ setGlobals globals
-    r <- pLua
-    c <- getCommonState
-    return (r, c)
-  putCommonState newState
-  return result
-
 instance {-# OVERLAPPING #-} Exposable PandocError (PandocLua NumResults) where
   partialApply _narg = liftLua . unPandocLua
 
 instance Pushable a => Exposable PandocError (PandocLua a) where
   partialApply _narg x = 1 <$ (liftLua (unPandocLua x >>= Lua.push))
 
--- | Global variables which should always be set.
-defaultGlobals :: PandocMonad m => m [Global]
-defaultGlobals = do
-  commonState <- getCommonState
-  return
-    [ PANDOC_API_VERSION
-    , PANDOC_STATE commonState
-    , PANDOC_VERSION
-    ]
-
 instance MonadError PandocError PandocLua where
   catchError = Catch.catch
   throwError = Catch.throwM
@@ -115,6 +79,22 @@ instance PandocMonad PandocLua where
   getCommonState = PandocLua $ do
     Lua.getglobal "PANDOC_STATE"
     forcePeek $ peekCommonState Lua.top
-  putCommonState = PandocLua . setGlobals . (:[]) . PANDOC_STATE
+  putCommonState cst = PandocLua $ do
+    pushCommonState cst
+    Lua.setglobal "PANDOC_STATE"
 
   logOutput = IO.logOutput
+
+-- | Retrieve a @'PandocError'@ from the Lua stack.
+popPandocError :: LuaE PandocError PandocError
+popPandocError = do
+  errResult <- runPeek $ peekPandocError top
+  case resultToEither errResult of
+    Right x -> return x
+    Left err -> return $ PandocLuaError (T.pack err)
+
+-- | Conversions between Lua errors and 'PandocError' exceptions.
+instance LuaError PandocError where
+  popException = popPandocError
+  pushException = pushPandocError
+  luaException = PandocLuaError . T.pack