I don't have much Rust-specific experience, but I wonder if you need a library for this when the language/compiler is doing all the heavy lifting. When working

I don't have much Rust-specific experience, but I wonder if you need a library for this when the language/compiler is doing all the heavy lifting. When working with Elm, for example, that uses that a lot for the Model-View-Update framework, you just define your model states and pattern match them to build the view and update functions.