1 files changed, 7 insertions, 5 deletions
diff --git a/ds/elem.go b/ds/elem.go
index 0589e81..22bc9d9 100644
--- a/ds/elem.go
+++ b/ds/elem.go
@@ -1,10 +1,12 @@
 package ds
 
 type Elem interface {
-	Equal(a Elem) bool
-	Lower(a Elem) bool
-	LowerEqual(a Elem) bool
-	Higher(a Elem) bool
-	HigherEqual(a Elem) bool
+	Equal(e Elem) bool
+	Lower(e Elem) bool
+	LowerEqual(e Elem) bool
+	Higher(e Elem) bool
+	HigherEqual(e Elem) bool
+	Compare(e Elem) int
+	CompareCB(e Elem, lowerCB, higherCB, equalsCB func())
 	Int() int
 }