1 files changed, 20 insertions, 0 deletions
diff --git a/reachability/walk.go b/reachability/walk.go
index 13400e89..e6de8684 100644
--- a/reachability/walk.go
+++ b/reachability/walk.go
@@ -15,3 +15,23 @@ type Walk struct {
 	seqUsed bool
 	err     error
 }
+
+// Walk creates one single-use traversal over the selected domain.
+//
+// In DomainCommits, when a commit-graph reader is attached, parent expansion
+// may use commit-graph metadata for speed.
+func (r *Reachability) Walk(domain Domain, haves, wants map[objectid.ObjectID]struct{}) *Walk {
+	walk := &Walk{
+		reachability: r,
+		domain:       domain,
+		haves:        haves,
+		wants:        wants,
+	}
+
+	err := validateDomain(domain)
+	if err != nil {
+		walk.err = err
+	}
+
+	return walk
+}