Author here. Besides creating Typo as an exercise in implementing a language, it's also the punchline to a seven-year-old joke[1] about implementing RSA in Haskell's type system, which I did:

  https://github.com/seliopou/typo/blob/master/examples/rsa.typo

Hopefully I'll have the time next week to write a blog post explaining how the encoding of functions work, as well as a cool transformation I employed to make the translation simpler than it otherwise would be.

Until then, enjoy!

[1]: http://article.gmane.org/gmane.comp.lang.haskell.general/132...