channelFlow was overkill for a single-producer chain. The cost was
an extra Channel hop between every projection.snapshot() and the
downstream collector — pure overhead with no concurrency benefit.
flow { } needs the outer collector captured (because inside
changes.onSubscription { ... } and changes.collect { ... } the
implicit `this` is FlowCollector<StoreChange>, not
FlowCollector<ProjectionState<T>>). One `val outer = this` fixes
that.
Backpressure now flows directly: a slow collector suspends emit,
which suspends our changes.collect, which suspends the SharedFlow's
buffer drain — natural propagation, no decoupling Channel in the
middle.
17/17 projection tests pass.
https://claude.ai/code/session_01Jny85MTu1ynKgFBgysfWu5
Claude
5755ab90b2