[greenrd]

I'm not sure I agree. Functional Reactive Programming is a declarative way of doing user interaction, but it's still a computer science research topic (Elm used to claim to be FRP, but has now decided to move away from its old allegedly FRP-like style). I need to play around with the latest FRP research libraries some time!

In addition there is also machines/pipes/conduits, which all mix imperative I/O with declarative style code in an interesting and new way.

[ayberkt]

FRP is awesome and is an example of how something previously thought of as an inherently imperative problem can be much easily done declaratively; we completely agree on this!

What I was talking about is: almost all lower-level abstractions are designed with the view of computer as a state machine. If we are solving a problem at an abstraction low enough to make us deal with this analogy, it is easier not to have a declarative layer in between.

machines/pipes/conduits are all very interesting and I was going to mention them too, but I still don't think they solve this problem in the way OP was referring to.