feat(pandocast): Support the lunajson parsing library as alternative

Alternative to luajson for JSON parsing.

README.md

@@ -88,9 +88,19 @@ Some *Djot* content
 
 ### Pandoc AST alternative package
 
-_Prerequisites:_ The [LuaJSON](https://github.com/harningt/luajson) module must be installed and available to your SILE environment.
-This topic is not covered here.
+_Prerequisites:_ Either [lunajson](https://github.com/grafi-tt/lunajson) or [LuaJSON](https://github.com/harningt/luajson) must be installed and available to your SILE environment. The former is recommended has no additional dependencies, and is straightforward to install:
 
+```shell
+luarocks install lunajson
+```
+
+The latter depends on the LPeg library, and this may require some additional tooling to be installed on your system (such as a C compiler, etc.). Moreover, as of 2024, the stable version has some issues, and you will need to install the development version instead:
+
+```shell
+luarocks install --dev luajson
+```
+
+Ready to go?
 First, using the appropriate version of Pandoc, convert your file to a JSON AST:
 
 ```shell

examples/sile-and-pandoc.dj

@@ -13,8 +13,13 @@ The following solution is still an experimental proof-of-concept, but you may gi
 ## Prerequisites
 
 Obviously, you need to have the Pandoc software installed on your system.
-You also need to have the LuaJSON module installed and available to your SILE environment.
-As of 2024, we recommend using the development version of the module, due to some issues with the current release version.
+You also need a JSON parser, and this collection comes by default with the *lunajson* module as pre-installed dependency.
+It is a Lua-only module, with no external dependencies, so it works out of the box.
+
+Another option is to use the *luajson* module, which is an LPeg-based parser, and might (or not) be more efficient in some cases.
+On some systems, it may however require the LPeg library to be compiled and installed.
+Luarocks{.nobreak} should take care of that for you, but it then assumes you have the necessary development tools on your system.
+Moreover, as of 2024, the current release version of the module has some issues, so we recommend using the development version instead:
 
 {custom-style=CodeBlock}
 :::
@@ -23,6 +28,8 @@ luarocks install --dev luajson
 ```
 :::
 
+If you have *luajson* installed, it is used instead of the default *lunajson* dependency.
+
 ## Using Pandoc's AST with the pandocast package
 
 The experimental *pandocast* package allows you to use Pandoc’s JSON AST as an input format for documents.

inputters/pandocast.lua

@@ -6,7 +6,7 @@
 -- AST conversion relies on the Pandoc types specification:
 -- https://hackage.haskell.org/package/pandoc-types
 --
--- Using the LuaJSON library for parsing.
+-- Using the luajson (LPEG-based) or lunajson (pure Lua) library for parsing.
 -- Reusing the common commands initially made for the "markdown" inputter/package.
 --
 -- @copyright License: MIT (c) 2022-2024 Omikhleia, Didier Willis
@@ -582,9 +582,16 @@ function inputter.appropriate (round, filename, doc)
 end
 
 function inputter:parse (doc)
+  -- Load JSON parser:
+  -- Luajson is LPEG-based, and lunajson is pure Lua without other
+  -- dependencies. Prioritize the former for if available, otherwise
+  -- fallback to lunajson, which we'll have in our dependencies.
   local has_json, json = pcall(require, "json.decode")
   if not has_json then
-    SU.error("The pandocast inputter requires LuaJSON's json.decode() to be available.")
+    has_json, json = pcall(require, "lunajson")
+    if not has_json then
+      SU.error("The pandocast inputter requires either luajson or lunajson to be available.")
+    end
   end
 
   local jsast = json.decode(doc)

rockspecs/markdown.sile-2.2.0-1.rockspec

@@ -0,0 +1,62 @@
+rockspec_format = "3.0"
+package = "markdown.sile"
+version = "2.2.0-1"
+source = {
+    url = "git+https://github.com/Omikhleia/markdown.sile.git",
+    tag = "v2.2.0",
+}
+description = {
+  summary = "Native Markdown support for the SILE typesetting system.",
+  detailed = [[
+    This package set for the SILE typesetting system provides a complete redesign
+    of the native Markdown support for SILE, with a great set of Pandoc-like
+    extensions and plenty of extra goodies.
+  ]],
+  homepage = "https://github.com/Omikhleia/markdown.sile",
+  license = "MIT",
+}
+dependencies = {
+   "lua >= 5.1",
+   "embedders.sile >= 0.2.0",
+   "labelrefs.sile >= 0.1.0",
+   "ptable.sile >= 3.1.0",
+   "smartquotes.sile >= 1.0.0",
+   "textsubsuper.sile >= 1.1.1",
+   "silex.sile >= 0.6.0, < 1.0",
+   "lunajson",
+}
+
+build = {
+   type = "builtin",
+   modules = {
+      ["sile.classes.markdown"]           = "classes/markdown.lua",
+      ["sile.inputters.markdown"]         = "inputters/markdown.lua",
+      ["sile.inputters.pandocast"]        = "inputters/pandocast.lua",
+      ["sile.inputters.djot"]             = "inputters/djot.lua",
+      ["sile.packages.markdown"]          = "packages/markdown/init.lua",
+      ["sile.packages.markdown.cmbase"]   = "packages/markdown/cmbase.lua",
+      ["sile.packages.markdown.commands"] = "packages/markdown/commands.lua",
+      ["sile.packages.markdown.utils"]    = "packages/markdown/utils.lua",
+      ["sile.packages.pandocast"]         = "packages/pandocast/init.lua",
+      ["sile.packages.djot"]              = "packages/djot/init.lua",
+
+      ["sile.lunamark"]                 = "lua-libraries/lunamark.lua",
+      ["sile.lunamark.entities"]        = "lua-libraries/lunamark/entities.lua",
+      ["sile.lunamark.reader"]          = "lua-libraries/lunamark/reader.lua",
+      ["sile.lunamark.reader.markdown"] = "lua-libraries/lunamark/reader/markdown.lua",
+      ["sile.lunamark.util"]            = "lua-libraries/lunamark/util.lua",
+      ["sile.lunamark.writer"]          = "lua-libraries/lunamark/writer.lua",
+      ["sile.lunamark.writer.generic"]  = "lua-libraries/lunamark/writer/generic.lua",
+      ["sile.lunamark.writer.html"]     = "lua-libraries/lunamark/writer/html.lua",
+      ["sile.lunamark.writer.html5"]    = "lua-libraries/lunamark/writer/html5.lua",
+
+      ["sile.djot"]                     = "lua-libraries/djot.lua",
+      ["sile.djot.attributes"]          = "lua-libraries/djot/attributes.lua",
+      ["sile.djot.json"]                = "lua-libraries/djot/json.lua",
+      ["sile.djot.block"]               = "lua-libraries/djot/block.lua",
+      ["sile.djot.inline"]              = "lua-libraries/djot/inline.lua",
+      ["sile.djot.html"]                = "lua-libraries/djot/html.lua",
+      ["sile.djot.ast"]                 = "lua-libraries/djot/ast.lua",
+      ["sile.djot.filter"]              = "lua-libraries/djot/filter.lua",
+   }
+}

rockspecs/markdown.sile-dev-1.rockspec

@@ -22,6 +22,7 @@ dependencies = {
    "smartquotes.sile",
    "textsubsuper.sile",
    "silex.sile",
+   "lunajson",
 }
 
 build = {