OK, I think it would be easiest for me to focus on the work I’ve done recently on translating Elm’s approach to JSON decoders into Purescript. That will touch on topics 2 and 3 – what to do when you want equality checking for functions (despite it being impossible), and simulating GADTs in Purescript using Leibniz equality.
That will be quicker for me to prepare than topic 1 – perhaps I can do that one in the future sometime.