[bsaul]

A bit of a sidenote but FSM for UI is a reason why algebraic data types systems like swift with its powerful enum is so valuable.

[arianvanp]

Basically the whole premise of https://elm-lang.org

[ken]

As a Smug Lisp Weenie myself, I'm glad that users of other languages are finally getting into the habit of posting "my programming language does that!" on every thread. That's one Lisp feature I thought might never be copied!