Mmhm! But not without confusing the hell out of everyone. But who cares? It's fun!

I should start by clarifying that I'm not associated with Arc in any way. Everything that I show should be thought of as an eager derivative, at best. But for several months a colleague and I have been working on a derivative, which we've been calling laarc, which incorporates a few additions that make it a bit easier to write programs with. Here's a debugger similar to pdb.set_trace(), for example: http://i.imgur.com/WWKa4kw.png Except when it breaks, it shows a list of the values of all the local variables. It's really useful for stepping through macro expansions and understanding them, because there's no longer any mystery when something breaks. Laarc isn't anywhere near ready yet, so it's too early to know whether it'll be useful generally, but the goal is to discover a way to make programming feel like a Tesla.

So, what are the benefits? Well, here's an example of a real-world program. It's all pimply and has a few hacks in it, but on the other hand, you can get a gist of how it might look: https://github.com/laarc/monki/blob/master/main.l

Note that this was made two days ago, and I've been working very fast. So it's pretty rough. The program (monki) is essentially "cp for git", and while it works, it's not quite finished. Monki is Yet Another alternative to git subtrees / submodules; think of it like "cp for git". `monki clone voltagex/foo foo` would create a clone of that repo into the subdir "foo". But that subdir can be within one of your existing repositories.

Here's the scenario it's useful for: https://github.com/tlbtlbtlb/startuptools

This requires an installation of tlbcore (https://github.com/tlbtlbtlb/tlbcore) symlinked to this directory.

With monki, you'd just type `monki clone tlbtlbtlb/tlbcore tlbcore` from within a clone of startuptools, and then you'd commit the result. Monki takes care of pulling updates, so that whenever tlbcore changes, startuptools would also get the new stuff. But you can `monki clone` a specific commit instead, if you want to pin to a "known working" version.

Anyway, that monki business was the result of trying to answer "What's a simple way where I can share code between all my repositories, pull in updates as I make them, and not have to worry too much?" And it was a good chance to exercise... Lumen!

Confused yet? Ok, so Arc runs on Racket. So did Laarc. Then we had the good fortune to hear about Lumen: https://github.com/sctb/lumen

It's a Lisp that compiles to either Javascript or Lua. It literally exhibits the same behavior whether you're running via luajit, node, or the browser. Since LuaJIT's FFI is awesome, that makes it incredibly easy to interface with existing C libraries using Lumen. Just look how beautiful his postgres bindings are! https://github.com/sctb/motor/blob/master/pq.l

That should catch anyone's attention -- the FFI is literally "copy paste some C declarations and you're done."

I want to take that further. In Lumen, it's already possible to interface with node libraries or with lua libraries as-needed. What if we extend it to work with python and go libs as easily as it works with C? You might end up with a language that could do any given task very easily, because you'd simply use whatever library happens to be convenient regardless of whether it's a C lib, a node package, or a Ruby gem.

So why have I been yakking about Lumen? Because it seems like it offers a bunch of interesting benefits as a runtime. I've been porting Laarc from Racket to it, slowly. It's extremely early, but here's an early version of the compiler: https://github.com/laarc/lumen-arc/blob/master/arc.l ... It's essentially ac.scm. I wanted to make it match as closely as possible, both because ac.scm is a good answer to "What's a good way to write a lisp compiler in a lisp language?" and because it's dangerous to assume you can write from scratch something that a smart team has been thinking about and working on for 13 years.

Sooo... That's a whirlwind tour of stuff that's not even ready to tour. On the plus side, the plan is to get an in-browser repl running soon (arc can already run in the browser, so it's a matter of coaxing CodeMirror into submission). There's a server running Lumen over at http://arc.lol:9999 which does absolutely nothing useful yet. The plan is to get a REPL up and to dub it "Arc dot tiefighter" since "lol" obviously looks like a tie fighter.