I'm not convinced that this is the best way to build widget toolkits rather than just how it's always been done. I'd like to see one built more on traits like IClickable instead of subclassing button.
HTML/CSS is already like this (for styling only), attributes can be mixed and matched.
I haven't actually done anything along this route myself, but I think the most promising approach is to model all the widgets as traits (and traits can depend on other traits, which lets you model the inheritance tree).
> Vala has been a great tool for prototyping, I love it myself, but debugging it is a nightmare, it’s filled with security issues and even if we fixed those really difficult problems, we’d be maintaining our own language on top of everything else. I would like to see us maintaining less stuff other than a desktop and the application development framework, not more.
Lack of inheritance is a shortage of Rust, but maybe we can have a kind of React-like GUI library for it.
It may 'compile' to C, but we've had Vala for quite a while now. Honestly, my biggest complaints are the syntax is so close to C# that I always find myself trying to do stupid things like `using System.Collections.Generic;` instead of Gee, etc. Oh, and it would be REALLY NICE if the compiler had support for custom attributes without needing to patch the compiler itself (even just for storing metadata would be hugely beneficial, but I don't see any reason why there can't be a plugin api for the codegen side of things either).
Rust is great and all, but every time I play with it I just don't see how it would work well with the complex inheritance tree that is a widget toolkit (meanwhile GObject works just fine, even if it's a little verbose at the C-level).