Some suggestions for Swift Observation

The SE-0395 sequences certainly have problems, and I believe they are an anti-pattern. The review thread is the place to mention them (many of us already have).

SE-0395 forces us into a bottom-up review: "can the provided apis fulfill reasonable needs?" This is a difficult exercise, because 1. reasoning from first principles is hard, and requires an abstract mindset 2. when first principles look sound, we do not dare criticizing them, even when they fail at fulfilling basic needs (we think "they look so smart, surely I'm a bad programmer…"). It's a pity, because the SE-0395 authors desire quality feedback.

That's why this thread uses a reversed top-down approach: start from reasonable use cases and the runtime guarantees they need, and infer apis from them. My hope is that it's much easier to judge the relevance of the suggestions.