Paul Chiusano

Functional programming, UX, tech, econ


Consulting services

I offer Scala and FP consulting services. If you're interested in working together, please contact me.

About my book

My book, Functional Programming in Scala, uses Scala as a vehicle for teaching FP. Read what people are saying about it.

Popular links

Unison: a next-gen programming platform the worldwide elastic computer (coming soon)
Type systems and UX: an example
CSS is unnecessary

Unison now open source and has its own site

I finally wrapped up most of the housecleaning I wanted to do before releasing the code. It’s now public on GitHub and there’s also a dedicated project site and blog at and Twitter account. Going forward, I’ll be posting about Unison from, and any contributors to the project will also be able to use that space for Unison-related posts.


Unison update 7: structured refactoring sessions

As I mentioned in update 6, I’ve been spending the last few weeks doing some much-needed refactoring. Here’s an update on the progress:


Unison update 6: refactoring, technical debt, and motivation

No new screencasts to show this week. I’m in the middle of doing some much-needed refactoring. What happened? As of the last update, I had a decent expression editor. The missing final piece was adding a declaration layer to the editor, allowing a Unison panel to be edited much like a module in a regular programming language.


I hate type errors!

I hate type errors!


Unison update 5: a better spreadsheet

Here’s a video of the latest progress. In this video, I create the term view reactive (1 + 1), which displays in the editor as 2. This might not seem like much, but the ability to define reactive views like this is the first step in allowing Unison panels to be used much like a spreadsheet, where the user fills in values and other parts of the panel are updated in response. There’s also a few other things shown which I’ll talk through below: