routing: extended DirectedNodePair functionality

routing/nodepair.go

@@ -1,6 +1,8 @@
 package routing
 
 import (
+	"fmt"
+
 	"github.com/lightningnetwork/lnd/routing/route"
 )
 
@@ -8,3 +10,21 @@ import (
 type DirectedNodePair struct {
 	From, To route.Vertex
 }
+
+// NewDirectedNodePair instantiates a new DirectedNodePair struct.
+func NewDirectedNodePair(from, to route.Vertex) DirectedNodePair {
+	return DirectedNodePair{
+		From: from,
+		To:   to,
+	}
+}
+
+// String converts a node pair to its human readable representation.
+func (d DirectedNodePair) String() string {
+	return fmt.Sprintf("%v -> %v", d.From, d.To)
+}
+
+// Reverse returns a reversed copy of the pair.
+func (d DirectedNodePair) Reverse() DirectedNodePair {
+	return DirectedNodePair{From: d.To, To: d.From}
+}