wait, Querier can just return an iter like eventstore, it's ok.

eventstore/wrappers/querier.go

@@ -1,26 +0,0 @@
-package wrappers
-
-import (
-	"context"
-
-	"fiatjaf.com/nostr"
-	"fiatjaf.com/nostr/eventstore"
-)
-
-var _ nostr.Querier = StoreQuerier{}
-
-type StoreQuerier struct {
-	eventstore.Store
-}
-
-func (w StoreQuerier) QueryEvents(ctx context.Context, filter nostr.Filter) (chan nostr.Event, error) {
-	ch := make(chan nostr.Event)
-
-	go func() {
-		for evt := range w.Store.QueryEvents(filter) {
-			ch <- evt
-		}
-	}()
-
-	return ch, nil
-}

interfaces.go

@@ -2,6 +2,7 @@ package nostr
 
 import (
 	"context"
+	"iter"
 )
 
 type Publisher interface {
@@ -9,7 +10,7 @@ type Publisher interface {
 }
 
 type Querier interface {
-	QueryEvents(context.Context, Filter) (chan Event, error)
+	QueryEvents(Filter) iter.Seq[Event]
 }
 
 type QuerierPublisher interface {

nip77/nip77.go

@@ -36,18 +36,15 @@ func NegentropySync(
 
 	vec := vector.New()
 	neg := negentropy.New(vec, 1024*1024)
-	ch, err := store.QueryEvents(ctx, filter)
-	if err != nil {
-		return err
-	}
 
-	for evt := range ch {
+	for evt := range store.QueryEvents(filter) {
 		vec.Insert(evt.CreatedAt, evt.ID)
 	}
 	vec.Seal()
 
 	result := make(chan error)
 
+	var err error
 	var r *nostr.Relay
 	r, err = nostr.RelayConnect(ctx, url, nostr.RelayOptions{
 		CustomHandler: func(data string) {
@@ -118,12 +115,7 @@ func NegentropySync(
 				if len(ids) == 0 {
 					return
 				}
-				evtch, err := dir.source.QueryEvents(ctx, nostr.Filter{IDs: ids})
-				if err != nil {
-					result <- fmt.Errorf("error querying source on %s: %w", dir.label, err)
-					return
-				}
-				for evt := range evtch {
+				for evt := range dir.source.QueryEvents(nostr.Filter{IDs: ids}) {
 					dir.target.Publish(ctx, evt)
 				}
 			}

relay.go

@@ -6,6 +6,7 @@ import (
 	"crypto/tls"
 	"errors"
 	"fmt"
+	"iter"
 	"log"
 	"net/http"
 	"strconv"
@@ -434,19 +435,21 @@ func (r *Relay) PrepareSubscription(ctx context.Context, filter Filter, opts Sub
 }
 
 // implement Querier interface
-func (r *Relay) QueryEvents(ctx context.Context, filter Filter) (chan Event, error) {
+func (r *Relay) QueryEvents(filter Filter) iter.Seq[Event] {
+	ctx, cancel := context.WithCancel(r.connectionContext)
+
+	return func(yield func(Event) bool) {
+		defer cancel()
+
 		sub, err := r.Subscribe(ctx, filter, SubscriptionOptions{Label: "queryevents"})
 		if err != nil {
-		return nil, err
+			return
 		}
 
-	ch := make(chan Event)
-
-	go func() {
 		for {
 			select {
 			case evt := <-sub.Events:
-				ch <- evt
+				yield(evt)
 			case <-sub.EndOfStoredEvents:
 				return
 			case <-sub.ClosedReason:
@@ -455,9 +458,7 @@ func (r *Relay) QueryEvents(ctx context.Context, filter Filter) (chan Event, err
 				return
 			}
 		}
-	}()
-
-	return ch, nil
+	}
 }
 
 // Count sends a "COUNT" command to the relay and returns the count of events matching the filters.