IsSuperSet()

hashset.go

@@ -7,7 +7,6 @@ Difference()
 DifferenceUpdate()
 Intersection()
 IntersectionUpdate()
-IsSuperset()
 SymmetricDifference()
 SymmetricDifferenceUpdate()
 Union()
@@ -107,6 +106,7 @@ func (s *Set[T]) IsDisjoint(other *Set[T]) bool {
 
 // IsSubset tests whether every element in this set
 // is contained in the other set.
+// empty sets are considered subsets of each other.
 func (s *Set[T]) IsSubset(other *Set[T]) bool {
 	if other.Len() < s.Len() {
 		return false
@@ -120,3 +120,10 @@ func (s *Set[T]) IsSubset(other *Set[T]) bool {
 	return true
 
 }
+
+// IsSuperset tests whether every element in other is
+// contained within this set.
+// empty sets are considered supersets of each other.
+func (s *Set[T]) IsSuperSet(other *Set[T]) bool {
+	return other.IsSubset(s)
+}

hashset_test.go

@@ -94,3 +94,24 @@ func TestIsSubsetNo(t *testing.T) {
 func TestEmptySetSubset(t *testing.T) {
 	assert.True(t, New[int](0).IsSubset(New[int](0)))
 }
+
+func TestIsSuperSetYes(t *testing.T) {
+	a := New(3, 1, 2, 3)
+	b := New(3, 3, 2, 1)
+	assert.True(t, a.IsSuperSet(b))
+	assert.True(t, b.IsSuperSet(a))
+
+	c := New(3, 1, 2, 3, 4, 5)
+	d := New(3, 2, 3, 4)
+	assert.True(t, c.IsSuperSet(d))
+}
+
+func TestIsSuperSetNo(t *testing.T) {
+	a := New(3, 1, 2, 3)
+	b := New(3, 2, 3)
+	assert.False(t, b.IsSuperSet(a))
+}
+
+func TestEmptySetSuperset(t *testing.T) {
+	assert.True(t, New[string](0).IsSuperSet(New[string](0)))
+}