So more like an algebraic effect system than what most people think of as exceptions? I definitely think that's a promising area, but unfortunately it's current

So more like an algebraic effect system than what most people think of as exceptions? I definitely think that's a promising area, but unfortunately it's currently still only really a thing in research experiments a-la Koka (https://www.microsoft.com/en-us/research/project/koka/ https://www.microsoft.com/en-us/research/project/koka/).