first commit

pkg/observable/subscriber.go

@@ -0,0 +1,33 @@
+package observable
+
+import (
+	"sync"
+)
+
+type Subscription <-chan any
+
+type Subscriber struct {
+	buffer chan any
+	once   sync.Once
+}
+
+func (s *Subscriber) Emit(item any) {
+	s.buffer <- item
+}
+
+func (s *Subscriber) Out() Subscription {
+	return s.buffer
+}
+
+func (s *Subscriber) Close() {
+	s.once.Do(func() {
+		close(s.buffer)
+	})
+}
+
+func newSubscriber() *Subscriber {
+	sub := &Subscriber{
+		buffer: make(chan any, 200),
+	}
+	return sub
+}