BitArray.IsEmpty()

bit_array.go

@@ -167,6 +167,20 @@ func (bA *BitArray) Sub(o *BitArray) *BitArray {
 	}
 }
 
+func (bA *BitArray) IsEmpty() bool {
+	if bA == nil {
+		return true // should this be opposite?
+	}
+	bA.mtx.Lock()
+	defer bA.mtx.Unlock()
+	for _, e := range bA.Elems {
+		if e > 0 {
+			return false
+		}
+	}
+	return true
+}
+
 func (bA *BitArray) IsFull() bool {
 	if bA == nil {
 		return true

bit_array_test.go

@@ -148,3 +148,19 @@ func TestBytes(t *testing.T) {
 	bA.SetIndex(9, true)
 	check(bA, []byte{0x80, 0x03})
 }
+
+func TestEmptyFull(t *testing.T) {
+	ns := []int{47, 123}
+	for _, n := range ns {
+		bA := NewBitArray(n)
+		if !bA.IsEmpty() {
+			t.Fatal("Expected bit array to be empty")
+		}
+		for i := 0; i < n; i++ {
+			bA.SetIndex(i, true)
+		}
+		if !bA.IsFull() {
+			t.Fatal("Expected bit array to be full")
+		}
+	}
+}