I think it’s a little misleading that the title of this post is «Gren - an Elm fork».
While technically correct, I think there are many who will be dissapointed to find that Gren and Elm are incompatible languages.
In addition to some syntax changes and improvements, Gren adds the support of a NodeJS target. It’s still early, so we don’t support all of the builtin APIs yet, but we’ll slowly get there.
AMA
I did find a news post listing some differences, but it didn't really go into "why". A dedicated page outlining the differences / opinions on the changes would help me determine if this is a language I might use.
Having a NodeJS (server) target is definitely interesting.
I also improved pattern matching on records to make them more ergonomic.
No automatic record constructors: same as the above, but in my experience it also confused beginners.
I know of several that actively avoids it in their projects, even enforcing it with a linter rule.
No GLSL: never used it, and don’t know how it works. It also broke when I upgraded the version of the Haskell compiler (Gren’s compiler is written in Haskell). For those reasons, it was removed.
No reactor: never used it
Did you mean better refactoring?
I got a bit too ambitious with the type system, I think. At the very least, I got to a point where I got discouraged because the type system I wanted was difficult to implement, and I started to realize that there were a few problems with the design. At the same time, I was starting to feel that this may not actually be something I'd want to use in production.
On the flip side, I learned a whole lot about web assembly that I hope to put into Gren. I also felt a lot of pain with the lack of FileSystem APIs in Elm (which Stabel was implemented in). In a way, my work on Stabel triggered the work on Gren.
Contributions welcome.