Fun of writing Unison

I gave this talk at:

- Lambda Days 2025
- FP AMS, 10.09.2025

Transcript

1. Fun of writing Unison Yoshikuni Kato FP AMS, 10.09.2025 1
2. Unison • Unison is a friendly programming language from the future: statically-typed, functional, and a lot of fun1 • ML-like syntax • Implemented in functional stack: Haskell, Elm • Have you used Unison before? 1 https://www.unison-lang.org/ 2
3. My libraries • @yoching/units - Unit conversion and calculation • @yoching/codable - Ergonomic data decoding and encoding • With Abilities Both on Unison Share. I will share how I write Unison with demo. 3
4. Unison Characteristics • Content-addressed & Unison Codebase Manager • Abilities: Algebraic Effects • Distributed computing & Unison Cloud • Unison Share: GitHub for Unison • Computable documentation 4
5. Content-addressed & UCM • functions/terms/types are referenced by hash of the Abstruct Syntax Tree. Names are aliases to the hash • Code is stored in a database as serialized AST with its hash (=“codebase”) • Tool to access the codebase = Unison Codebase Manager 5
6. Live Demo 6
7. Unison experience • Updating codebase is safe, easy, and quick • Substitutes a lot of work IDEs currently do • Future of programming? • Unison is a friendly programming language from the future 7
8. Tips • Get used to the tooling first. Ability (algebraic effects) next • There is Dutch Unison Meetup • Check #meetups of Unison Discord 8
9. Yoshikuni Kato • Software engineer since 2013, ! -> " -> # , University of Tokyo alumni • Now freelancing • TS/Swift/Python for client projects, Elm/Unison for OSS • Organizing Amsterdam Casual FP meetup - unconference style • Open to new projects soon (maybe FP?) 9