Improve how Lua client evaluates a form

[russtoku]

I made a small change to how the Lua client handles ee (evaluate form under cursor). I noticed that I would have to select a region and use E to evaluate a function defintion block. Improvements were made very easily thanks to Tree-sitter.

I've also added some comments to the dev/lua/sandbox.lua file to try to document some behavior when evaluating code. I'm not sure if that's the appropriate place to put them.

[russtoku]

Sorry, I didn't realize that another commit to the develop branch would piggy-back that commit on top of this PR.

[Olical]

Ohh nice, thanks a lot! I'll take a look and promise to reply to your email question about the stdio support rewrite, will probably do so in an open discussion on GitHub though as a sort of RFC.

[Olical]

LGTM, tried it out locally and I'm happy. Great changes and very good understanding of the contraptions I've made 😄

[russtoku]

Thanks! I'm trying to get a better understanding of how things are put together.
Thanks again for a very handy plugin. It's helping me get on with the various languages I'm interested in getting better with.

[glyh]

@russtoku If you want further improvement on this maybe you can try to find if there's a way to implement "real" REPL, because the current implementation is using debug module, that means you either loose local variables across evaluation, or you can't use the debug module when using conjure within neovim. That's a thing I didn't figure out how to do.

[russtoku]

@glyh , I created #504 to capture your suggestion. This way others might be able to help. Sorry but at this point, I don't know enough of the details of the Lua client to imagine how to approach it.