The Kibit rule system (jonase.github.io)

I really like tools like these! The one I use for Haskell is hlint[1].

1: http://community.haskell.org/~ndm/hlint/

I note that the overtone jazz composition has been updated since this presentation was put together. :)

I hate what these slides do to my browser history.

At first I thought this would be talking about kibits, now collaborate: http://www.collaborate.com/

These are called rewrite rules and you can find a lot of previous work on this to reference and build on.

Hmmm

  (defrules my-rules
    [(+ ?x 1) (inc ?x)]
    [(- ?x 1) (dec ?x)])

Could something like that be shipped together with libraries and automagically update and refactor my code on simple backward incompatible changes?