I’m not necessarily against splitting out queryF (and the other constructors), but I also don’t think it’s a problem to maintain this separately downstream — I think it’s pretty rare to do that and this code doesn’t really change. I might like to wait for @garyb to have a chance to weigh in.

As a side note, I’m curious — what are you using run-Halogen for? Looks interesting!

run-halogen was split out of a side project I wrote to learn purescript. I don't think I can open source it; it was implementing the character generation process of the old pencil and paper RPG Traveler, and I think the process is copyrighted. The basic idea was to write the "business logic" using a bunch of domain specific algebraic effects (roll a die, choose from these options, enter a string etc.) plus State. I wrote a CLI version where these interactions are built around readline and the default state implementation, and a halogen version where the interactions are each delegated to a specific widget component and the state is the halogen state, so the page renders the state changes.