I'm translating David Christiansen's bidirectional typechecking Haskell example into Swift. Why would I do such a thing? It's not because Swift is especially well-suited to this task! I want to learn about type checking in dependently typed languages, and I want to learn more about Swift, so, well, why not?

This project is an incomplete work in progress.

David said

Please feel free to use or adapt [the examples] for your own purposes.

But he didn't specify a particular license. So I'm posting this version under the MIT license.

(You only need to do this once.)

If you don't already have the Swift command-line tools, install them via:

$ xcode-select --install

You will need swift-format. I installed this via Homebrew, as follows, but any method of installation should work so long as it ends up on your PATH

$ brew install swift-format

$ make test

...and, that's it! There is no executable for now, it's just library code.