Switch to hslua-2.0

The new HsLua version takes a somewhat different approach to marshalling
and unmarshalling, relying less on typeclasses and more on specialized
types. This allows for better performance and improved error messages.

Furthermore, new abstractions allow to document the code and exposed
functions.

1 files changed, 49 insertions, 57 deletions

diff --git a/src/Text/Pandoc/Lua/Marshaling/ReaderOptions.hs b/src/Text/Pandoc/Lua/Marshaling/ReaderOptions.hs
index dd7bf2e61..2cc39ee3a 100644
--- a/src/Text/Pandoc/Lua/Marshaling/ReaderOptions.hs
+++ b/src/Text/Pandoc/Lua/Marshaling/ReaderOptions.hs
@@ -1,4 +1,3 @@
-{-# LANGUAGE LambdaCase           #-}
 {-# LANGUAGE OverloadedStrings    #-}
 {-# LANGUAGE ScopedTypeVariables  #-}
 {-# OPTIONS_GHC -fno-warn-orphans #-}
@@ -13,67 +12,60 @@
 
 Marshaling instance for ReaderOptions and its components.
 -}
-module Text.Pandoc.Lua.Marshaling.ReaderOptions () where
+module Text.Pandoc.Lua.Marshaling.ReaderOptions
+  ( peekReaderOptions
+  , pushReaderOptions
+  ) where
 
-import Data.Data (showConstr, toConstr)
-import Foreign.Lua (Lua, Pushable)
-import Text.Pandoc.Extensions (Extensions)
-import Text.Pandoc.Lua.Marshaling.AnyValue (AnyValue (..))
-import Text.Pandoc.Lua.Marshaling.CommonState ()
-import Text.Pandoc.Options (ReaderOptions (..), TrackChanges)
-
-import qualified Data.Set as Set
-import qualified Data.Text as Text
-import qualified Foreign.Lua as Lua
-import qualified Text.Pandoc.Lua.Util as LuaUtil
+import HsLua as Lua
+import Text.Pandoc.Lua.Marshaling.List (pushPandocList)
+import Text.Pandoc.Options (ReaderOptions (..))
 
 --
 -- Reader Options
 --
-instance Pushable Extensions where
-  push exts = Lua.push (show exts)
 
-instance Pushable TrackChanges where
-  push = Lua.push . showConstr . toConstr
+peekReaderOptions :: LuaError e => Peeker e ReaderOptions
+peekReaderOptions = peekUD typeReaderOptions
+
+pushReaderOptions :: LuaError e => Pusher e ReaderOptions
+pushReaderOptions = pushUD typeReaderOptions
 
-instance Pushable ReaderOptions where
-  push ro = do
-    let ReaderOptions
-          (extensions            :: Extensions)
-          (standalone            :: Bool)
-          (columns               :: Int)
-          (tabStop               :: Int)
-          (indentedCodeClasses   :: [Text.Text])
-          (abbreviations         :: Set.Set Text.Text)
-          (defaultImageExtension :: Text.Text)
-          (trackChanges          :: TrackChanges)
-          (stripComments         :: Bool)
-          = ro
-    Lua.newtable
-    LuaUtil.addField "extensions" extensions
-    LuaUtil.addField "standalone" standalone
-    LuaUtil.addField "columns" columns
-    LuaUtil.addField "tab_stop" tabStop
-    LuaUtil.addField "indented_code_classes" indentedCodeClasses
-    LuaUtil.addField "abbreviations" abbreviations
-    LuaUtil.addField "default_image_extension" defaultImageExtension
-    LuaUtil.addField "track_changes" trackChanges
-    LuaUtil.addField "strip_comments" stripComments
+typeReaderOptions :: LuaError e => DocumentedType e ReaderOptions
+typeReaderOptions = deftype "pandoc ReaderOptions"
+  [ operation Tostring luaShow
+  ]
+  [ readonly "extensions" ""
+      ( pushString . show
+      , readerExtensions)
+  , readonly "standalone" ""
+      ( pushBool
+      , readerStandalone)
+  , readonly "columns" ""
+      ( pushIntegral
+      , readerColumns)
+  , readonly "tab_stop" ""
+      ( pushIntegral
+      , readerTabStop)
+  , readonly "indented_code_classes" ""
+      ( pushPandocList pushText
+      , readerIndentedCodeClasses)
+  , readonly "abbreviations" ""
+      ( pushSet pushText
+      , readerAbbreviations)
+  , readonly "track_changes" ""
+      ( pushString . show
+      , readerTrackChanges)
+  , readonly "strip_comments" ""
+      ( pushBool
+      , readerStripComments)
+  , readonly "default_image_extension" ""
+      ( pushText
+      , readerDefaultImageExtension)
+  ]
 
-    -- add metatable
-    let indexReaderOptions :: AnyValue -> AnyValue -> Lua Lua.NumResults
-        indexReaderOptions _tbl (AnyValue key) = do
-          Lua.ltype key >>= \case
-            Lua.TypeString -> Lua.peek key >>= \case
-              ("defaultImageExtension" :: Text.Text)
-                                    -> Lua.push defaultImageExtension
-              "indentedCodeClasses" -> Lua.push indentedCodeClasses
-              "stripComments" -> Lua.push stripComments
-              "tabStop" -> Lua.push tabStop
-              "trackChanges" -> Lua.push trackChanges
-              _ -> Lua.pushnil
-            _ -> Lua.pushnil
-          return 1
-    Lua.newtable
-    LuaUtil.addFunction "__index" indexReaderOptions
-    Lua.setmetatable (Lua.nthFromTop 2)
+luaShow :: LuaError e => DocumentedFunction e
+luaShow = defun "__tostring"
+  ### liftPure show
+  <#> udparam typeReaderOptions "state" "object to print in native format"
+  =#> functionResult pushString "string" "Haskell representation"