mmm: copy new lmdb querying mechanism because it's so much more elegant.

eventstore/mmm/replace.go

@@ -2,6 +2,7 @@ package mmm
 
 import (
 	"fmt"
+	"iter"
 	"math"
 	"runtime"
 
@@ -33,16 +34,20 @@ func (il *IndexingLayer) ReplaceEvent(evt nostr.Event) error {
 
 		return il.lmdbEnv.Update(func(iltxn *lmdb.Txn) error {
 			// now we fetch the past events, whatever they are, delete them and then save the new
-			prevResults, err := il.query(iltxn, filter, 10) // in theory limit could be just 1 and this should work
+			var yield_ func(nostr.Event) bool
+			var results iter.Seq[nostr.Event] = func(yield func(nostr.Event) bool) {
+				yield_ = yield
+			}
+			err := il.query(iltxn, filter, 10 /* in theory limit could be just 1 and this should work */, yield_)
 			if err != nil {
 				return fmt.Errorf("failed to query past events with %s: %w", filter, err)
 			}
 
 			shouldStore := true
-			for _, previous := range prevResults {
-				if internal.IsOlder(previous.Event, evt) {
-					if err := il.delete(mmmtxn, iltxn, previous.Event.ID); err != nil {
-						return fmt.Errorf("failed to delete event %s for replacing: %w", previous.Event.ID, err)
+			for previous := range results {
+				if internal.IsOlder(previous, evt) {
+					if err := il.delete(mmmtxn, iltxn, previous.ID); err != nil {
+						return fmt.Errorf("failed to delete event %s for replacing: %w", previous.ID, err)
 					}
 				} else {
 					// there is a newer event already stored, so we won't store this