After spending a decade focusing mostly on Haskell, I have spent the last three years looking deeply at OCaml. This talk will capture some lessons learned about my work in the two languages and their communities – how they are similar, how they differ, and how each might usefully grow to become more like the other. I will compare Haskell’s purity against OCaml’s support for mutation, type classes against modules as abstraction paradigms, laziness against strictness, along with some general thoughts about language philosophy. We’ll also touch on the some of the challenges both languages face as open-source products, in need of both volunteers and funding. While some functional programming experience will definitely be helpful, I’ll explain syntax as we go – no Haskell or OCaml knowledge required, as I want this talk to be accessible equally to the two communities.

Software Engineer at Jane Street. I believe that clever application of theory can eliminate a great deal of programmer errors – specifically, I think fancy types and functional programming are the future. I completed my PhD in 2016 at University of Pennsylvania working under Stephanie Weirich; my dissertation topic was the integration of dependent types into the Haskell programming language. My work now centers around improvements to OCaml’s type system to empower more performant programming – without sacrificing safety. In addition, I am a contributor to the Glasgow Haskell Compiler (GHC) and frequent collaborator on its type system and implementation.