Much better structelem support

luamml-amsmath.lua

@@ -89,6 +89,7 @@ lua.get_functions_table()[funcid] = function()
   local columns = node.count(node.id'align_record', tex.lists.align_head)//2
   mml_table.columnalign = kind == 'align' and string.rep('right left', columns, ' ') or nil
   mml_table.width = kind == 'multline' and '100%' or nil
+  -- mml_table.side = kind == 'multline' and 'rightoverlap' or nil
   local spacing = {}
   for n in node.traverse_id(node.id'glue', tex.lists.align_head) do
     spacing[#spacing+1] = n.width == 0 and '0' or '.8em'

luamml-convert.lua

@@ -139,7 +139,7 @@ local function delim_to_table(delim)
   else
     local fam = delim.small_fam
     char = remap_lookup[fam << 21 | char]
-    local result = {[0] = 'mo', char, ['tex:family'] = fam ~= 0 and fam or nil, stretchy = not stretchy[char] or nil, lspace = 0, rspace = 0, [':node'] = delim }
+    local result = {[0] = 'mo', char, ['tex:family'] = fam ~= 0 and fam or nil, stretchy = not stretchy[char] or nil, lspace = 0, rspace = 0, [':nodes'] = {delim} }
     if mathml_filter then
       return mathml_filter(result, result)
     else
@@ -166,7 +166,7 @@ local function acc_to_table(acc, cur_style, stretch)
   if stretch ~= not stretchy[char] then -- Handle nil gracefully in stretchy
     stretch = nil
   end
-  local result = {[0] = 'mo', char, ['tex:family'] = fam ~= 0 and fam or nil, stretchy = stretch, [':node'] = acc}
+  local result = {[0] = 'mo', char, ['tex:family'] = fam ~= 0 and fam or nil, stretchy = stretch, [':nodes'] = {acc}}
   if mathml_filter then
     return mathml_filter(result)
   else
@@ -190,7 +190,7 @@ local function kernel_to_table(kernel, cur_style)
       char,
       ['tex:family'] = fam ~= 0 and fam or nil,
       mathvariant = utf8.len(char) == 1 and elem == 'mi' and utf8.codepoint(char) < 0x10000 and 'normal' or nil,
-      [':node'] = kernel,
+      [':nodes'] = {kernel},
     }
     if mathml_filter then
       return mathml_filter(result, result)
@@ -202,7 +202,7 @@ local function kernel_to_table(kernel, cur_style)
     if kernel.list.id == hlist_t then -- We directly give up for vlists
       result = to_text(kernel.list.head)
     else
-      result = {[0] = 'mi', {[0] = 'mglyph', ['tex:box'] = kernel.list, [':node'] = kernel}}
+      result = {[0] = 'mi', {[0] = 'mglyph', ['tex:box'] = kernel.list, [':nodes'] = {kernel}}}
     end
     if mathml_filter then
       return mathml_filter(result, result)
@@ -272,6 +272,15 @@ local function noad_to_table(noad, sub, cur_style, joining)
           or core[0] == 'mn' or text_families[core['tex:family']] then
         if joining and core[0] == joining[0] and core['tex:family'] == joining['tex:family'] then
           joining[#joining+1] = core[1]
+          local cnodes = core[':nodes']
+          if cnodes then -- very likely
+            local jnodes = joining[':nodes']
+            if jnodes then -- very likely
+              table.move(cnodes, 1, #cnodes, #jnodes+1, jnodes)
+            else
+              joining[':nodes'] = cnodes
+            end
+          end
           nucleus = do_sub_sup(joining, joining, noad, cur_style)
           if nucleus == joining then
             return nil, joining, joining

luamml-structelemwriter.lua

@@ -39,8 +39,9 @@ local mc_type = token.create'l__tag_mc_type_attr'.index
 local mc_cnt = token.create'l__tag_mc_cnt_attr'.index
 -- print('!!!', mc_type, mc_cnt)
 
+local stash_cnt = 0
 local attrs = {}
-local function write_elem(tree, indent)
+local function write_elem(tree, stash)
   if tree[':struct'] then
     return tex.runtoks(function()
       return tex.sprint(struct_use, '{', tree[':struct'], '}')
@@ -54,22 +55,34 @@ local function write_elem(tree, indent)
     attrs[i] = string.format('/%s(%s)', escape_name(attr), escape_string(val))
   end end
   table.sort(attrs)
-  local attr_name
+
-  if i == 0 then
+  if stash then
-    tex.sprint(struct_begin, '{tag=', tree[0], '/mathml}')
+    stash_cnt = stash_cnt + 1
+    stash = '__luamml_stashed_' .. stash_cnt
+    tree[':struct'] = stash
+    stash = ', stash, label = ' .. stash
   else
-    tex.sprint(struct_begin, '{tag=', tree[0], '/mathml,attribute=', attributes[table.concat(attrs)], '}')
+    stash = ''
+  end
+
+  if i == 0 then
+    tex.sprint(struct_begin, '{tag=' .. tree[0] .. '/mathml' .. stash .. '}')
+  else
+    tex.sprint(struct_begin, '{tag=' .. tree[0] .. '/mathml, attribute=' .. attributes[table.concat(attrs)] .. stash .. '}')
   end
   for j = 1, i do attrs[j] = nil end
 
-  if tree[':node'] then
+  if tree[':nodes'] then
-    local n = tree[':node']
+    local n = tree[':nodes']
     tex.runtoks(function()
       tex.sprint{mc_begin, string.format('{tag=%s}', tree[0])}
       -- NOTE: This will also flush all previous sprint's... That's often annoying, but in this case actually intentional.
     end)
-    node.set_attribute(tree[':node'], mc_type, tex.attribute[mc_type])
+    local mct, mcc = tex.attribute[mc_type], tex.attribute[mc_cnt]
-    node.set_attribute(tree[':node'], mc_cnt, tex.attribute[mc_cnt])
+    for i = 1, #n do
+      node.set_attribute(n[i], mc_type, mct)
+      node.set_attribute(n[i], mc_cnt, mcc)
+    end
     tex.runtoks(function()
       tex.sprint(mc_end)
     end)
@@ -84,6 +97,6 @@ local function write_elem(tree, indent)
   end)
 end
 
-return function(element)
+return function(element, stash)
-  return write_elem(element)
+  return write_elem(element, stash)
 end

luamml-tex.lua

@@ -83,6 +83,9 @@ local function save_result(xml, display, structelem)
   if tracing then
     texio.write_nl(write_xml(mlist_result) .. '\n')
   end
+  if tex.count.l__luamml_flag_int & 8 == 8 then
+    write_struct(mlist_result)
+  end
   return mlist_result
 end
 
@@ -95,11 +98,11 @@ luatexbase.add_to_callback('pre_mlist_to_hlist_filter', function(mlist, style)
     return true
   end
   local display = style == 'display'
+  local startmath = tex.nest.top.tail -- Must come before any write_struct calls which adds nodes
   style = flag & 4 == 4 and flag>>5 & 0x7 or display and 0 or 2
   local xml, core = process_mlist(mlist, style)
-  local processed_xml
   if flag & 2 == 2 then
-    processed_xml = save_result(shallow_copy(xml), display)
+    save_result(shallow_copy(xml), display)
   else
     local element_type = token.get_macro'l__luamml_root_tl'
     if element_type ~= 'mrow' then
@@ -109,19 +112,17 @@ luatexbase.add_to_callback('pre_mlist_to_hlist_filter', function(mlist, style)
         xml = {[0] = element_type, xml}
       end
     end
-    processed_xml = xml
   end
   if not display and flag & 1 == 1 then
-    local startmath = tex.nest.top.tail
     local props = properties[startmath]
     if not props then
       props = {}
       properties[startmath] = props
     end
     props.saved_mathml_table, props.saved_mathml_core = xml, core
+    if flag & 10 == 8 then
+      write_struct(xml, true) -- This modifies xml in-place to reference the struture element
     end
-  if flag & 8 == 8 then
-    write_struct(shallow_copy(processed_xml), display and 0 or 2)
   end
   return true
 end, 'dump_list')

luamml.dtx

@@ -102,6 +102,19 @@
 %    \end{macrocode}
 % \end{macro}
 %
+% \begin{macro}{\__luamml_maybe_structelem:}
+% A internal helper which can be added to a tag to preserve the external state
+% of the structelem flag.
+%    \begin{macrocode}
+\cs_new:Npn \__luamml_maybe_structelem: {
+  (
+    8 * \int_mod:nn {
+      \int_div_truncate:nn { \l__luamml_flag_int } {8}
+    } {2}
+  ) +
+}
+% \end{macro}
+%
 % \begin{macro}{\luamml_flag_save:,
 %               \luamml_flag_save:N,
 %               \luamml_flag_save:n,
@@ -118,17 +131,17 @@
 %   cases.
 %    \begin{macrocode}
 \cs_new_protected:Npn \luamml_flag_save: {
-  \int_set:Nn \l__luamml_flag_int { 1 }
+  \int_set:Nn \l__luamml_flag_int { \__luamml_maybe_structelem: 1 }
 }
 \cs_new_protected:Npn \luamml_flag_save:N #1 {
-  \int_set:Nn \l__luamml_flag_int { 17 + 32 * #1 }
+  \int_set:Nn \l__luamml_flag_int { \__luamml_maybe_structelem: 17 + 32 * #1 }
 }
 \cs_new_protected:Npn \luamml_flag_save:n {
-  \int_set:Nn \l__luamml_flag_int { 5 }
+  \int_set:Nn \l__luamml_flag_int { \__luamml_maybe_structelem: 5 }
   \tl_set:Nn \l__luamml_root_tl
 }
 \cs_new_protected:Npn \luamml_flag_save:Nn #1 {
-  \int_set:Nn \l__luamml_flag_int { 21 + 32 * #1 }
+  \int_set:Nn \l__luamml_flag_int { \__luamml_maybe_structelem: 21 + 32 * #1 }
   \tl_set:Nn \l__luamml_root_tl
 }
 %    \end{macrocode}