New Type Checker!

[Eric Holk]

I've spent the last week rewriting our type and region inferencer. As of a couple of minutes ago, all of our test cases pass, including some tests that were broken under the old system.

This version does not use miniKanren or cKanren anymore, although writing it felt like re-implementing miniKanren. We now do region inference at the same time as type inference. They were conceptually very similar, and now since both happen early on, region inference is much faster.

We aren't yet doing true region- or type-polymorphism, although we're a lot closer than we used to be. I'll be adding more test cases soon to figure out exactly the limits of the new system. Hopefully we can add these missing features before long.

-Eric

[Eric Holk]

Just to add to this, I was able to get a very simple breadth first search program working. It doesn't exactly produce the search tree yet, but it does do the traversal in the right order. You can see it at https://github.iu.edu/eholk/harlan/blob/master/test/bench-bfs.kfc