align support and fixes

luamml-amsmath.lua

@@ -0,0 +1,84 @@
+local write_xml = require'luamml-xmlwriter'
+local make_root = require'luamml-convert'.make_root
+
+local properties = node.get_properties_table()
+
+local funcid = luatexbase.new_luafunction'luamml_amsmath_add_box_to_row:'
+token.set_lua('luamml_amsmath_add_box_to_row:', funcid, 'protected')
+lua.get_functions_table()[funcid] = function()
+  -- TODO: Error handling etc
+  -- local box = token.scan_int()
+  local boxnum = 0
+  local startmath = tex.box[boxnum].list
+  assert(startmath.id == node.id"math")
+  local props = assert(properties[startmath])
+  local mml = assert(props.saved_mathml_table)
+  table.insert(mml, 1, {[0] = 'maligngroup'})
+  if mml[0] == 'mstyle' and mml.displaystyle == true then
+    mml[0], mml.displaystyle, mml.scriptlevel = 'mtd', nil, nil
+  else
+    if mml[0] ~= 'mstyle' then
+      mml = {[0] = 'mstyle', displaystyle = false, mml}
+    end
+    mml = {[0] = 'mtd', mml}
+  end
+  local row_temp = tex.nest[tex.nest.ptr-1]
+  print(row_temp)
+  props = properties[row_temp]
+  if not props then
+    props = {}
+    properties[row_temp] = props
+  end
+  if not props.mathml_row then
+    props.mathml_row = {[0] = 'mtr'}
+  end
+  mml_row = props.mathml_row
+  table.insert(mml_row, mml)
+end
+
+local funcid = luatexbase.new_luafunction'luamml_amsmath_finalize_row:'
+token.set_lua('luamml_amsmath_finalize_row:', funcid, 'protected')
+lua.get_functions_table()[funcid] = function()
+  -- TODO: Error handling etc
+  local row_temp = tex.nest[tex.nest.ptr-1]
+  print("final", row_temp)
+  local props = properties[row_temp]
+  if not props then return end
+  if not props.mathml_row then return end
+  mml_row = props.mathml_row
+  props = properties[tex.lists.align_head]
+  if not props then
+    props = {}
+    properties[tex.lists.align_head] = props
+  end
+  local mml_table = props.mathml_table_node_table
+  if not mml_table then
+    mml_table = {[0] = 'mtable', displaystyle = true}
+    props.mathml_table_node_table = mml_table
+  end
+  table.insert(mml_table, mml_row)
+end
+
+local funcid = luatexbase.new_luafunction'luamml_amsmath_finalize_table:'
+token.set_lua('luamml_amsmath_finalize_table:', funcid)
+lua.get_functions_table()[funcid] = function()
+  -- TODO: Error handling etc
+  local props = properties[tex.lists.align_head]
+  if not props then return end
+  local mml_table = props.mathml_table_node_table
+  if not mml_table then return end
+  print(write_xml(make_root(mml_table, 2)))
+end
+
+funcid = luatexbase.new_luafunction'luamml_last_math_alignmark:'
+token.set_lua('luamml_last_math_alignmark:', funcid, 'protected')
+lua.get_functions_table()[funcid] = function()
+  local n = tex.nest.top.tail
+  n = n.nucleus or n
+  local props = properties[n]
+  if not props then
+    props = {}
+    properties[n] = props
+  end
+  props.mathml_table = {[0] = 'malignmark'}
+end

luamml-convert.lua

@@ -77,7 +77,7 @@ local function kernel_to_table(kernel, cur_style)
     local result = {[0] = elem,
       char,
       ['tex:family'] = fam ~= 0 and fam or nil,
-      mathvariant = #char == 1 and utf8.codepoint(char) < 0x10000 and 'normal' or nil
+      mathvariant = #char == 1 and elem == 'mi' and utf8.codepoint(char) < 0x10000 and 'normal' or nil
     }
     return result, result
   elseif id == sub_box_t then
@@ -256,7 +256,10 @@ function nodes_to_table(head, cur_style)
     elseif id == accent_t then
       t[#t+1], new_core = accent_to_table(n, sub, cur_style)
     elseif id == style_t then
-      if #t ~= 0 then
+      if sub ~= cur_style then
+        if #t == 0 then
+          t[0] = 'mstyle'
+        else
           local new_t = {[0] = 'mstyle'}
           t[#t+1] = new_t
           t = new_t
@@ -267,6 +270,7 @@ function nodes_to_table(head, cur_style)
           t.displaystyle, t.scriptlevel = false, sub//2 - 1
         end
         cur_style = sub
+      end
       new_core = space_like
     elseif id == choice_t then
       local size = cur_style//2
@@ -312,18 +316,22 @@ local function register_remap(family, mapping)
   end
 end
 
-local function to_mml(head, style)
-  local result = nodes_to_table(head, style or 0)
-  result[0] = 'math'
-  result.xmlns = 'http://www.w3.org/1998/Math/MathML'
-  result['xmlns:tex'] = 'http://typesetting.eu/2021/LuaMathML'
-  if style == 2 then
-    result.display = 'block'
+local function to_math(root, style)
+  if root[0] == 'mrow' then
+    root[0] = 'math'
+  else
+    root = {[0] = 'math', root}
   end
-  return result
+  root.xmlns = 'http://www.w3.org/1998/Math/MathML'
+  root['xmlns:tex'] = 'http://typesetting.eu/2021/LuaMathML'
+  if style < 2 then
+    root.display = 'block'
+  end
+  return root
 end
 
 return {
   register_family = register_remap,
-  process = to_mml,
+  process = function(head, style) return nodes_to_table(head, style or 2) end,
+  make_root = to_math,
 }

luamml-patches-amsmath.sty

@@ -0,0 +1,99 @@
+\ProvidesExplPackage {luamml-patches-amsmath} {2021-04-23} {0.0.1-alpha}
+  {Feel free to add a description here}
+
+\lua_now:n { require'luamml-amsmath' }
+
+\cs_set:Npn \align@preamble {
+  &
+    \hfil
+    \strut@
+    \setboxz@h {
+      \@lign
+      $
+        \m@th
+        \displaystyle {
+          ##
+        }
+        \ifmeasuring@
+          \luamml_flag_ignore:
+        \else
+          \luamml_flag_alignment_left:
+        \fi
+      $
+    }
+    \ifmeasuring@
+      \savefieldlength@
+    \fi
+    \set@field
+    \tabskip\z@skip
+  &
+    \setboxz@h {
+      \@lign
+      $
+      \m@th
+      \displaystyle
+      {
+        {}
+        \luamml_last_math_alignmark:
+        ##
+      }
+      \ifmeasuring@
+        \luamml_flag_ignore:
+      \else
+        \luamml_flag_alignment_right:
+      \fi
+      $
+    }
+    \ifmeasuring@
+      \savefieldlength@
+    \else
+      \luamml_amsmath_add_box_to_row:
+    \fi
+    \set@field
+    \hfil
+    \tabskip\alignsep@
+}
+
+\cs_set:Npn \math@cr@@@align {
+  \ifst@rred
+    \nonumber
+  \fi
+  \if@eqnsw
+    \global \tag@true
+  \fi
+  \global \advance \row@ \@ne
+  \add@amps \maxfields@
+  \omit
+  \kern -\alignsep@
+  \luamml_amsmath_finalize_row:
+  \iftag@
+    \setboxz@h { 
+      \@lign
+      \strut@
+      { \make@display@tag }
+    }
+    \place@tag
+  \fi
+  \ifst@rred
+  \else
+    \global \@eqnswtrue
+  \fi
+  \global \lineht@ \z@
+  \cr
+}
+
+\cs_set:Npn \endalign {
+  \math@cr
+  \black@ \totwidth@
+  \luamml_amsmath_finalize_table:
+  \egroup
+  \ifingather@
+    \restorealignstate@
+    \egroup
+    \nonumber
+    \ifnum0=‘{\fi\iffalse}\fi
+  \else
+    $$
+  \fi
+  \ignorespacesafterend
+}

luamml-tex.lua

@@ -1,10 +1,13 @@
 local mlist_to_mml = require'luamml-convert'
 local process_mlist = mlist_to_mml.process
+local make_root = mlist_to_mml.make_root
 local register_family = mlist_to_mml.register_family
 
 local mappings = require'luamml-legacy-mappings'
 local write_xml = require'luamml-xmlwriter'
 
+local properties = node.get_properties_table()
+
 local funcid = luatexbase.new_luafunction'RegisterFamilyMapping'
 token.set_lua('RegisterFamilyMapping', funcid, 'protected')
 lua.get_functions_table()[funcid] = function()
@@ -17,10 +20,56 @@ lua.get_functions_table()[funcid] = function()
   end
 end
 
+-- Possible flag values:
+--   0: Normal (This is the only supported one in display mode)
+--   1: Like 0, result is display math
+--   2: Generate MathML, but only save it for later usage in startmath node
+--   3: Skip
+--   4: Prepend node list from buffer before generating
+--   5: Like 5, result is display math
+--   6: 2+4
+--   7: Skip but save copy of node list in buffer
+--
+--  In other words:
+--    Bit 1: Suppress output
+--    Bit 0: Force display if 1 isn't set, if it is then skip MathML generation
+--    Bit 2: Integrate with table mechanism
+
+local mlist_buffer
+
 luatexbase.add_to_callback('pre_mlist_to_hlist_filter', function(mlist, style)
-  print''
-  local xml = process_mlist(mlist, style == 'display' and 2 or 0)
-  print(write_xml(xml))
-  print''
+  local flag = tex.count.l__luamml_flag_int
+  if flag & 3 == 3 then
+    if flag & 4 == 4 then
+      assert(mlist_buffer == nil)
+      mlist_buffer = node.copy_list(mlist)
+    end
+    return true
+  end
+  local new_mlist, buffer_tail
+  if flag & 4 == 4 then
+    new_mlist, buffer_tail = assert(mlist_buffer), node.tail(mlist_buffer)
+    mlist.prev, buffer_tail.next = buffer_tail, mlist
+    mlist_buffer = nil
+  else
+    new_mlist = mlist
+  end
+  local xml = process_mlist(new_mlist, style == 'display' and 0 or 2)
+  if flag & 2 == 0 then
+    print(write_xml(make_root(xml, (style == 'display' or flag & 1 == 1) and 0 or 2)) .. '\n')
+  else
+    assert(style == 'text')
+    local startmath = tex.nest.top.tail
+    local props = properties[startmath]
+    if not props then
+      props = {}
+      properties[startmath] = props
+    end
+    props.saved_mathml_table = xml
+  end
+  if buffer_tail then
+    mlist.prev, buffer_tail.next = nil, nil
+    node.flush_list(new_mlist)
+  end
   return true
 end, 'dump_list')

luamml.sty

@@ -0,0 +1,17 @@
+\ProvidesExplPackage {luamml} {2021-04-23} {0.0.1-alpha}
+  {Feel free to add a description here}
+
+\int_new:N \l__luamml_flag_int
+\lua_now:n { require'luamml-tex' }
+
+\cs_new:Nn \luamml_flag_ignore: {
+  \int_set:Nn \l__luamml_flag_int { 3 }
+}
+\cs_new:Nn \luamml_flag_alignment_left: {
+  \int_set:Nn \l__luamml_flag_int { 7 }
+}
+\cs_new:Nn \luamml_flag_alignment_right: {
+  \int_set:Nn \l__luamml_flag_int { 6 }
+}
+
+\RequirePackage { luamml-patches-amsmath }

test_tex.tex

@@ -1,11 +1,12 @@
 \documentclass{article}
-% \usepackage{unicode-math}
-\directlua{require'luamml-tex'}
+\usepackage{unicode-math}
+\usepackage{amsmath}
+\usepackage{luamml}
 \RegisterFamilyMapping\symsymbols{oms}
 \RegisterFamilyMapping\symletters{oml}
 \begin{document}
 \[
-  ax^2+b+c=0
+  ax^2+bx+c=0
 \]
 \[
   x = \frac{-b \pm \sqrt{b^2-4ac}}{2a}.
@@ -14,5 +15,11 @@
   \sum_a\underline c\dot bc'
 \]
 
+\begin{align}
+  abc&=def\\
+  1+2&=3\\
+  5
+\end{align}
+
 Es gilt $\sin(x)-\sin(x+2\pi)=0$.
 \end{document}