.

wcfs/δbtail_test.go

@@ -339,11 +339,13 @@ func IntSets(N int) chan []int {
 func intSets(ch chan []int, lo, hi int) {
 	ch <- []int{}   // ø
 
-	if lo < hi-1 {
-		chTail := make(chan []int)
-		go intSets(chTail, lo+1, hi)
-		for tail := range chTail {
-			ch <- append([]int{lo}, tail...) // lo + tail
+	for i := lo; i < hi; i++ {
+		if i < hi-1 {
+			chTail := make(chan []int)
+			go intSets(chTail, i+1, hi)
+			for tail := range chTail {
+				ch <- append([]int{i}, tail...) // i + tail
+			}
 		}
 	}
 
@@ -357,7 +359,12 @@ func TestIntSets(t *testing.T) {
 	}
 
 	I := func(v ...int) []int { return v }
-	want := [][]int{I(), I(0), I(1), I(2) /* XXX */}
+	want := [][]int{I(),
+			I(0),
+			I(0,1), I(0,2), I(0,1,2),
+			I(1),
+			I(2),
+		}
 
 	if !reflect.DeepEqual(got, want) {
 		t.Fatalf("error:\ngot:  %v\nwant: %v", got, want)