Lua filters: add SimpleTable for backwards compatibility (#6575)

A new type `SimpleTable` is made available to Lua filters. It is
similar to the `Table` type in pandoc versions before 2.10;
conversion functions from and to the new Table type are provided.

Old filters using tables now require minimal changes and can use,
e.g.,

    if PANDOC_VERSION > {2,10,1} then
      pandoc.Table = pandoc.SimpleTable
    end

and

    function Table (tbl)
      tbl = pandoc.utils.to_simple_table(tbl)
      …
      return pandoc.utils.from_simple_table(tbl)
    end

to work with the current pandoc version.

1 files changed, 24 insertions, 0 deletions

diff --git a/data/pandoc.lua b/data/pandoc.lua
index d031bf5d0..35ca20a84 100644
--- a/data/pandoc.lua
+++ b/data/pandoc.lua
@@ -1058,6 +1058,30 @@ M.ListAttributes.behavior.__pairs = function(t)
   return make_next_function(fields), t, nil
 end
 
+--
+-- Legacy and compatibility types
+--
+
+--- Creates a simple (old style) table element.
+-- @function SimpleTable
+-- @tparam      {Inline,...} caption    table caption
+-- @tparam      {AlignDefault|AlignLeft|AlignRight|AlignCenter,...} aligns alignments
+-- @tparam      {int,...}    widths     column widths
+-- @tparam      {Block,...}  headers    header row
+-- @tparam      {{Block,...}} rows      table rows
+-- @treturn     Block                   table element
+M.SimpleTable = function(caption, aligns, widths, headers, rows)
+  return {
+    caption = ensureInlineList(caption),
+    aligns = List:new(aligns),
+    widths = List:new(widths),
+    headers = List:new(headers),
+    rows = List:new(rows),
+    tag = "SimpleTable",
+    t = "SimpleTable",
+  }
+end
+
 
 ------------------------------------------------------------------------
 -- Constants