[WIP] Walk cells

src/Text/Pandoc/Lua/Marshal/Cell.hs-boot

@@ -0,0 +1,35 @@
+{- |
+Copyright               : © 2021-2024 Albert Krewinkel
+SPDX-License-Identifier : MIT
+Maintainer              : Albert Krewinkel <[email protected]>
+
+Marshaling/unmarshaling functions of table 'Cell' values.
+-}
+module Text.Pandoc.Lua.Marshal.Cell
+  ( peekCell
+  , peekCellFuzzy
+  , pushCell
+  , typeCell
+  , mkCell
+  ) where
+
+import HsLua
+import Text.Pandoc.Definition
+
+-- | Push a table cell as a table with fields @attr@, @alignment@,
+-- @row_span@, @col_span@, and @contents@.
+pushCell :: LuaError e => Cell -> LuaE e ()
+
+-- | Retrieves a 'Cell' object from the stack.
+peekCell :: LuaError e => Peeker e Cell
+
+-- | Retrieves a 'Cell' from the stack, accepting either a 'pandoc Cell'
+-- userdata object or a table with fields @attr@, @alignment@, @row_span@,
+-- @col_span@, and @contents@.
+peekCellFuzzy :: LuaError e => Peeker e Cell
+
+-- | Cell object type.
+typeCell :: LuaError e => DocumentedType e Cell
+
+-- | Constructor function for 'Cell' values.
+mkCell :: LuaError e => DocumentedFunction e

src/Text/Pandoc/Lua/Marshal/Shared.hs

@@ -16,6 +16,7 @@ import Prelude hiding (lookup)
 import Control.Monad ((>=>))
 import HsLua
 import {-# SOURCE #-} Text.Pandoc.Lua.Marshal.Block
+import {-# SOURCE #-} Text.Pandoc.Lua.Marshal.Cell
 import {-# SOURCE #-} Text.Pandoc.Lua.Marshal.Inline
 import Text.Pandoc.Lua.Marshal.Filter
 import Text.Pandoc.Definition
@@ -82,3 +83,11 @@ applyFilterTopdown filter' topdown@(Topdown _ node) =
           (inlines, ctrl) <-
             applyStraightFunction fn pushInlines peekInlinesFuzzy xs
           pure $ Topdown ctrl $ TInlines inlines
+    TCell c ->
+      case "Cell" `lookup` filter' of
+        Nothing ->
+          pure topdown
+        Just fn -> do
+          (cell, ctrl) <-
+            applyStraightFunction fn pushCell peekCellFuzzy c
+          pure $ Topdown ctrl $ TCell cell

src/Text/Pandoc/Lua/Topdown.hs

@@ -30,6 +30,8 @@ data TraversalNode
   | TBlocks [Block]
   | TInline Inline
   | TInlines [Inline]
+  -- | TRow Row
+  | TCell Cell
 
 -- | Type used to traverse a 'Pandoc' AST from top to bottom, i.e.,
 -- processing the root element first and then continue towards the
@@ -56,6 +58,8 @@ nodeBlocks = \case
   TBlock x    -> [x]
   TInlines xs -> [Plain xs]
   TInline x   -> [Plain [x]]
+  TCell c     -> let Cell _attr _align _rowspan _colspan blks = c
+                 in blks
 
 -- | Creates a topdown-walking function for a list of elements.
 walkTopdownM :: (Monad m, Walkable Topdown a)