I turned off the typechecker in order to get the C bootstrap to compile itself. The OCaml compiler compiles to a term which is evaluated by a simple small-step evaluator on a stack of closures, it can't handle deeply nested evaluations. I need to know whether it's able to compile itself, otherwise I'll need to backport the C back-end to the ML compiler. Guess I'll start on unit tests again. It's actually quite hard to derive unit tests for interfaces. Going to check Haskell on that, my interfaces are essentially type classes on type constructors, so the difference shouldn't be that big.
 Not ideal, but OCaml runs out of stack space easily. So, I build an explicit evaluator on a stack. Which is correct, but naive, it allocates 1Gb on some of the bigger files. The rewriter is pretty naive, and uses some unknown fact that the semantics of eager LC can be expressed on just a stack of closures, whereas most publications use some three tuple of a stack and some other stuff.