Add LuaMetaLaTeX and LuaMetaPlain support

.github/workflows/build-test-bundle.yml

@@ -26,6 +26,7 @@ jobs:
           sudo apt-get install --no-install-recommends -y
           poppler-utils
           xsltproc
+          libcurl4-openssl-dev
           ) & disown
 
       # From https://github.com/zauguin/install-texlive
@@ -92,6 +93,19 @@ jobs:
           echo "tl_context=$HOME/texlive/bin/x86_64-linux/context" >> $GITHUB_ENV
           echo "TEXMFHOME=$GITHUB_WORKSPACE/texmf" >> $GITHUB_ENV
 
+      - name: Install LuaMetaLaTeX
+        run: |
+          cd ~
+          git clone --depth 1 https://github.com/zauguin/luametalatex.git
+          cd luametalatex
+          l3build install
+          mktexlsr
+
+          cd ~
+          wget https://lmltx.typesetting.eu/installer-linux64.zip
+          unzip installer-linux64.zip
+          ./installer
+
       - name: Build Documentation
         run: |
           cd "$GITHUB_WORKSPACE"

CHANGELOG.md

@@ -11,6 +11,8 @@ All notable changes to lua-widow-control will be listed here, in reverse chronol
 
 ## Unreleased
 
+- Add support for [LuaMetaLaTeX and LuaMetaPlain](https://github.com/zauguin/luametalatex). All features should work identically to the LuaTeX-based version, although there are a few minor bugs. ([#40](https://github.com/gucci-on-fleek/lua-widow-control/pull/40))
+
 - Fully support inserts/footnotes in LuaMetaTeX ([#38](https://github.com/gucci-on-fleek/lua-widow-control/issues/38)).
 
 - Add support for presets in ConTeXt.

docs/manual/lwc-manual.tex

@@ -295,6 +295,10 @@ \subsection{\ConTeXt{}}
 \subsection{\OpTeX{}}
 \Lwc/ works with any version of \OpTeX{} and has no dependencies.
 
+\subsection{LuaMeta\TeX{}}
+
+\Lwc/ has preliminary support for LuaMeta\LaTeX{} and LuaMetaPlain. All features should work identically to the \LuaTeX{}-based version, although there are a few minor bugs. You should always make sure to use the latest engine, format, and \lwc/ since these formats are under rapid development.
+
 
 \section[sec:usage]{Loading the Package}
 

source/lua-widow-control.lua

@@ -59,14 +59,18 @@ end
 local format = tex.formatname
 local context, latex, plain, optex, lmtx
 
+if status.luatex_engine == "luametatex" then
+    lmtx = true
+end
+
 if format:find("cont") then -- cont-en, cont-fr, cont-nl, ...
     context = true
-    if status.luatex_engine == "luametatex" then
-        lmtx = true
-    end
 elseif format:find("latex") then -- lualatex, lualatex-dev, ...
     latex = true
-elseif format == "luatex" or format == "luahbtex" then -- Plain
+elseif format == "luatex" or
+       format == "luahbtex" or
+       format:find("plain")
+then -- Plain
     plain = true
 elseif format:find("optex") then -- OpTeX
     optex = _G.optex
@@ -89,6 +93,12 @@ local line_subid = 1
 local linebreakpenalty_subid = 1
 local par_id = id_from_name("par") or id_from_name("local_par")
 local penalty_id = id_from_name("penalty")
+local parfill_subids = {
+    parfillleftskip = 17,
+    parfillrightskip = 16,
+    parinitleftskip = 19,
+    parinitrightskip = 18,
+}
 
 -- Local versions of globals
 local abs = math.abs
@@ -105,6 +115,7 @@ local new_node = node.new
 local remove = node.remove
 local set_attribute = node.set_attribute or node.setattribute
 local string_char = string.char
+local subtype = node.subtype
 local tex_box = tex.box
 local tex_count = tex.count
 local tex_dimen = tex.dimen
@@ -143,7 +154,9 @@ local contrib_head,
       insert_attribute,
       max_cost,
       pagenum,
+      page_head,
       paragraph_attribute,
+      set_whatsit_field,
       shrink_order,
       stretch_order,
       warning
@@ -155,11 +168,15 @@ if lmtx then
     shrink_order = "shrinkorder"
     stretch_order = "stretchorder"
     hold_head = "holdhead"
+    page_head = "pagehead"
+    set_whatsit_field = node.setwhatsitfield
 else
     contrib_head = "contrib_head"
     shrink_order = "shrink_order"
     stretch_order = "stretch_order"
     hold_head = "hold_head"
+    page_head = "page_head"
+    set_whatsit_field = node.setfield
 end
 
 if context then
@@ -225,6 +242,7 @@ else -- This shouldn't ever happen
 Please use LaTeX, Plain TeX, ConTeXt or OpTeX.]]
 end
 
+
 --[[ Select the fonts
 
      We want to use cmr7 for the draft mode cost displays, and the easiest
@@ -349,6 +367,38 @@ local function next_of_type(head, id, args)
 end
 
 
+--- Ensures that a paragraph is ready to be broken
+---
+--- Only applies to LMTX
+--- @param head node
+--- @return nil
+local function prepare_linebreak(head)
+    if not lmtx then
+        return
+    end
+
+    local parfills = {}
+    local count = 0
+    for name, subid in pairs(parfill_subids) do
+        parfills[name] = next_of_type(head, glue_id, { subtype = subid })
+        if parfills[name] then
+            count = count + 1
+        end
+    end
+
+    if count == 0 then
+        -- Usual case
+        tex.preparelinebreak(head)
+    elseif count == 4 then
+        -- Already prepared for some reason, ignored
+    else
+        -- Uh oh
+        warning("Weird par(fill/init)skips found!")
+        tex.preparelinebreak(head) -- Try to fix it
+    end
+end
+
+
 --- Breaks a paragraph one line longer than natural
 ---
 --- @param head node The unbroken paragraph
@@ -358,9 +408,7 @@ local function long_paragraph(head)
     -- We can't modify the original paragraph
     head = copy_list(head)
 
-    if lmtx then
-        tex.preparelinebreak(head)
-    end
+    prepare_linebreak(head)
 
     -- Prevent ultra-short last lines (\TeX{}Book p. 104), except with narrow columns
     -- Equivalent to \\parfillskip=0pt plus 0.8\\hsize
@@ -387,9 +435,7 @@ local function natural_paragraph(head)
     -- We can't modify the original paragraph
     head = copy_list(head)
 
-    if lmtx then
-        tex.preparelinebreak(head)
-    end
+    prepare_linebreak(head)
 
     -- Break the paragraph naturally to get \\prevgraf
     local natural_node, natural_info = linebreak(head)
@@ -430,14 +476,14 @@ local function colour_list(head, colour)
 
     -- Adapted from https://tex.stackexchange.com/a/372437
     -- \\pdfextension colorstack is ignored in LMTX
-    local start_colour = new_node("whatsit", "pdf_colorstack")
-    start_colour.stack = 0
-    start_colour.command = 1
-    start_colour.data = pdf_colour
+    local start_colour = new_node("whatsit", subtype("pdf_colorstack"))
+    set_whatsit_field(start_colour, "stack", 0)
+    set_whatsit_field(start_colour, "command", 1)
+    set_whatsit_field(start_colour, "data", pdf_colour)
 
-    local end_colour = new_node("whatsit", "pdf_colorstack")
-    end_colour.stack = 0
-    end_colour.command = 2
+    local end_colour = new_node("whatsit", subtype("pdf_colorstack"))
+    set_whatsit_field(end_colour, "stack", 0)
+    set_whatsit_field(end_colour, "command", 2)
 
     start_colour.next = head
     last(head).next = end_colour
@@ -755,7 +801,7 @@ local function remove_widows_fail()
     warning("Widow/Orphan/broken hyphen NOT removed on page " .. pagenum())
 
     local last_line = next_of_type(
-        last(tex_lists.page_head),
+        last(tex_lists[page_head]),
         hlist_id,
         { subtype = line_subid, reverse = true }
     )
@@ -886,23 +932,34 @@ local function get_inserts(last_line)
 
         if lmtx then
             insert_box = tex.getinsertcontent(class)
+            tex.setinsertcontent(class, insert_box)
         else
             insert_box = tex_box[class]
         end
 
         -- Get any portions of the insert held over until the next page
-        local split_insert = next_of_type(
-            tex_lists[hold_head],
-            insert_id,
-            { subtype = class }
-        )
+        local split_insert
+        if lmtx then
+            split_insert = next_of_type(
+                tex_lists[hold_head],
+                insert_id,
+                { index = class }
+            )
+        else
+            split_insert = next_of_type(
+                tex_lists[hold_head],
+                insert_id,
+                { subtype = class }
+            )
+        end
 
         for i, insert in ipairs { insert_box, split_insert } do
             local m = insert and insert.list
 
             while m do -- Iterate through the insert box
                 local box_value
                 box_value, m = find_attribute(m, insert_attribute)
+                local next = m.next
 
                 if not m then
                     break
@@ -918,10 +975,10 @@ local function get_inserts(last_line)
                         table.insert(selected_inserts, copy(inserts[box_value]))
                     end
 
-                    m = free(m)
-                else
-                    m = m.next
+                    free(m)
                 end
+
+                m = next
             end
         end
 
@@ -1039,7 +1096,19 @@ end
 --- @param head node
 --- @param paragraph_index number
 local function replace_paragraph(head, paragraph_index)
-    local target_node = copy_list(paragraphs[paragraph_index].node)
+    -- Remove any inserts
+    local target_node, last_target_node
+    for n in traverse(paragraphs[paragraph_index].node) do
+        if n.id ~= insert_id then
+            if not target_node then
+                target_node = copy(n)
+                last_target_node = target_node
+            else
+                last_target_node.next = copy(n)
+                last_target_node = last_target_node.next
+            end
+        end
+    end
 
     local start_found = false
     local end_found = false

source/lua-widow-control.sty

@@ -145,6 +145,14 @@
     \fi
 }
 
+\prg_new_conditional:Nnn \__lwc_if_lmtx: { T, F, TF } {
+    \int_compare:nNnTF { \tex_luatexversion:D } > { 200 } {
+        \prg_return_true:
+    } {
+        \prg_return_false:
+    }
+}
+
 % Expansion of some parts of the document, such as section headings, is quite
 % undesirable, so we'll disable \lwc/ for certain commands.
 \int_new:N \g__lwc_disable_int
@@ -197,6 +205,12 @@
     \clist_map_function:NN \g__lwc_disablecmds_cl \__lwc_patch_cmd:n
 }
 
+\__lwc_if_lmtx:T {
+    \int_gset:Nn \normalizelinemode {
+        \numexpression\normalizelinemode bor 2\relax
+    }
+}
+
 %%% Class and package-specifc patches
 
 % KOMA-Script

source/lua-widow-control.tex

@@ -14,6 +14,9 @@
 
 \catcode`@=11
 
+% We need to change some code if we're using LuaMetaTeX
+\def\lwc@iflmtx{\ifnum\luatexversion>200\relax}
+
 \input ltluatex % \LuaTeX{}Base
 
 \clubpenalty=1
@@ -32,12 +35,20 @@
 % Here, we enable font expansion/contraction. It isn't strictly necessary for
 % \lwc/'s functionality; however, it is required for the
 % lengthened paragraphs to not have terrible spacing.
-\expandglyphsinfont\the\font 20 20 5
-\adjustspacing=2
+\lwc@iflmtx\else
+    \expandglyphsinfont\the\font 20 20 5
+    \adjustspacing=2
+\fi
 
 % Enable \lwc/ by default when the package is loaded.
 \lwc@enable
 
+% Fix some strange LMTX bugs
+\lwc@iflmtx
+    \normalizelinemode=\numexpression\normalizelinemode bor 2\relax
+\fi
+
+
 % Expansion of some parts of the document, such as section headings, is quite
 % undesirable, so we'll disable \lwc/ for certain commands.
 
@@ -80,7 +91,9 @@
 }
 
 \begingroup
-    \suppressoutererror=1
+    \lwc@iflmtx\else
+        \suppressoutererror=1
+    \fi
     \lwcdisablecmd{\beginsection} % Sectioning
 \endgroup
 

tests/common/luametatex-wrapper

@@ -0,0 +1,11 @@
+#!/bin/sh
+# lua-widow-control
+# https://github.com/gucci-on-fleek/lua-widow-control
+# SPDX-License-Identifier: MPL-2.0+
+# SPDX-FileCopyrightText: 2022 Max Chernoff
+set -eu
+
+format=$(echo "$@" | sed -E 's/^.*--fmt=([^ ]*) .*$/\1/')
+filename=$(echo "$@" | sed -E 's/^.*\input ([^ ]*).*$/\1/')
+
+exec "$format" "$filename"