Observer snapshot dispatch
The listener list can change while an event is running. SignalLedge keeps observer code, ordering examples and proposed edits together so callback behavior can be examined in your Windows project.
def notify(observers, event):
snapshot = tuple(observers)
if not all(callable(fn) for fn in snapshot):
raise ValueError("callable observers required")
for callback in snapshot:
callback(event)- Connection
- Base URL, credentials and a reachable server.
- Project
- Test subscriptions changed by a callback and a thrown exception, applying list changes only to later notifications and propagating the error immediately.
- Review before applying
- Compare actual behavior with the expected result. If a check fails, investigate it before applying more changes.
def notify(observers, event):
snapshot = tuple(observers)
if not all(callable(fn) for fn in snapshot):
raise ValueError("callable observers required")
for callback in snapshot:
callback(event)Make callback behavior part of the development brief
An event can reach the right callbacks and still leave the application in an unexpected state. SignalLedge offers a Windows AI coding workspace for investigating the code between event production and listener behavior. Begin with a concrete event sequence, the result you observed and the result you intended. Ask the connected assistant to locate the dispatch path and explain which parts of that sequence the implementation establishes.
The observer-snapshot example gives you one possible task: examine what happens when listener registration changes during notification. You could request a proposal that makes the intended behavior explicit and checks that registered entries are callable. Discuss failures in callbacks separately, because taking a snapshot does not define an error policy. Review the dispatch code together with the listeners that rely on it.
An uncensored AI model is an option when your supported OpenAI-compatible or Anthropic endpoint provides one. Configure credentials as needed and check the model's tool support and context limits. Provider restrictions still apply. After reviewing proposed edits, run event-sequence tests in your project. A separate local model server handles that model connection only; it does not ensure that every other connected tool runs locally.
Before changing event dispatch
What should happen if a listener adds another listener?
Define whether the new listener receives the current event or only later events. Then inspect the dispatch implementation against that decision. The snapshot example suggests a boundary to examine, but your application's required semantics should determine the requested change.
Does taking a snapshot handle callback exceptions?
No exception policy follows from copying the listener collection. Decide whether dispatch stops, continues or reports failures another way, then review the corresponding code. Include a failing listener in project tests if that behavior matters to your application.
How do I describe an event-order defect?
List the events in order, the listeners registered before each event and the observed callbacks. Keep the sequence small enough to reproduce. This evidence helps distinguish registration changes from a defect in the work performed by a listener.
Should dispatch and listener code change in the same patch?
Only where the requested behavior requires both. Ask for an explanation of each affected file and review the contract between them. Unrelated listener changes can make it harder to establish which edit corrected the reported sequence.
SignalLedge · Updated 2026-10-25