This blog post is also an IHaskell notebook and the source is available separately. I also did a talk at NYHUG based on this material. I wanted an explanation for HAMTs (Hash Array Mapped Tries) that was more detailed than Marek Majkowski’s introduction and more approachable than Ideal Hash Trees by Phil Bagwell, the paper that introduced them. If you haven’t heard of them before, HAMTs are a way