This seems like the subject part of RxSwift/Combine without any of the useful parts. For example, the networking example requires an explicit property whereas the code I would use for something like this would be to return an Observable directly. For most use cases, you don't have to handle state separately. Basically, this seems more complicated than using something like callbacks with this only having some very edge case benefits to that.

This is a good exercise but how is this better than Combine?

Also - I've seen ultra over complicated codebases made with FRP in Swift. I have some PTSD from the kickstarter MVVM approach. What a nightmare in practice. You have to be all in - everything FRP or the tightly bound system crumbles.

I think SwiftUI's @Published property wrapper elegantly hid the FRP, but even Apple is moving away from FRP with the macro based Observable framework.

Serious question: isn't this kind of thing already built in to swiftui?

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