[chadaustin]

First, let me say that I think Evan has done amazing work with Elm, and Elm is a very interesting language on several fronts. It is a positive contribution to the world, especially the idea that error messages can be great and compilers and type systems are tools.

That said, I agree 100% that the ability to form abstractions is a critical part of any language that hopes to become a tool that larger teams and projects can adopt. Without type classes and convenient mutability, I don't see Elm achieving widespread adoption. (That said, it could gain those features in the future.)

I've been working on a language inspired to some degree by Elm but also by my experience teaching Haskell. Haskell has amazing expressive capabilities and type safety, but the unfamiliar syntax is a hurdle that many people don't care to jump. To that end, we've designed Crux to have much of the expressive power of languages in the ML/Haskell family, while being as familiar and lightweight as JavaScript or Python. The idea is that it's something you can pick up easily but it can grow with you and your project.

Some articles on the design thinking: https://chadaustin.me/tag/crux/

The website: http://cruxlang.org [It's a preview!]