Make pandoc behave like a Lua interpreter when called as pandoc-lua.

[tarleb]

A program name of pandoc-lua, e.g., when the binary was invoked through a symlink with that name, will make pandoc behave like a Lua interpreter: the first command line argument is run as a Lua script, and the remaining arguments are passed to the interpreter in the global table arg. Lua options are not supported yet.

[tarleb]

Todo:

• docs
• possibly add support for more CLI options
• 🔜 medium term: extract the runScript function into an HsLua package
• 🔜 medium term: ensure signals like SIGTERM are handled in the way that the lua binary handles them.
• ❔ later: find a way to give script authors access to pandoc's cli parsing

[jgm]

Nice. Is an interactive REPL possible?

[jgm]

If we had a REPL, it might be worth adding some fancy pretty-printing of the userdata Haskell values, similar to https://github.com/wlupton/pandoc-lua-logging

[tarleb]

I'd like to do a REPL-less version first to avoid the need for an additional library (like haskeline). But it would be great to add one if the extra dependencies turn out to be small.

[jgm]

I think you'd add the following dependencies with haskeline:
Win32 nats unbuildable stm semigroups
That's not huge. And assuming we split the package, these would only be dependencies of pandoc-cli, not pandoc library.

[tarleb]

The current state is quite usable already and ready to merge from my side.

I plan to write a "hslua-cli" package, with a proper REPL, in the not-too-distant future. But I'd like to finish some other things first (e.g., Markdown tables).

[jgm]

Can you add a doc/pandoc-lua.md and adjust Makefile so it can be compiled to man/pandoc-lua.1 just as we now handle doc/pandoc-server.md?

[tarleb]

Done. 👍

BTW, to avoid complications, I'd like to limit support of the hslua-cli package to Lua 5.4. This would mean that we'd need to drop support for the lua53 flag at that point.

[tarleb]

I've extracted most of the code to the new package hslua-cli and fixed some more issues along the way. I'm dabbling with haskeline and may try isocline as well.