include existing logic

common.go

@@ -0,0 +1,18 @@
+package gubgub
+
+// Subscriber is a func that processes a message and returns true if it should continue processing more messages.
+type Subscriber[T any] func(T) bool
+
+// Topic is just a convenience interface you can expect all topics to implement.
+type Topic[T any] interface {
+	Publishable[T]
+	Subscribable[T]
+}
+
+type Publishable[T any] interface {
+	Publish(msg T) error
+}
+
+type Subscribable[T any] interface {
+	Subscribe(Subscriber[T]) error
+}