2 files changed, 14 insertions, 12 deletions
diff --git a/src/pkg/container/heap/example_pq_test.go b/src/pkg/container/heap/example_pq_test.go
index 8cbeb8d70..7017095cb 100644
--- a/src/pkg/container/heap/example_pq_test.go
+++ b/src/pkg/container/heap/example_pq_test.go
@@ -52,13 +52,12 @@ func (pq *PriorityQueue) Pop() interface{} {
 
 // update modifies the priority and value of an Item in the queue.
 func (pq *PriorityQueue) update(item *Item, value string, priority int) {
-	heap.Remove(pq, item.index)
 	item.value = value
 	item.priority = priority
-	heap.Push(pq, item)
+	heap.Fix(pq, item.index)
 }
 
-// This example inserts some items into a PriorityQueue, manipulates an item,
+// This example creates a PriorityQueue with some items, adds and manipulates an item,
 // and then removes the items in priority order.
 func Example_priorityQueue() {
 	// Some items and their priorities.
@@ -66,28 +65,31 @@ func Example_priorityQueue() {
 		"banana": 3, "apple": 2, "pear": 4,
 	}
 
-	// Create a priority queue and put the items in it.
-	pq := &PriorityQueue{}
-	heap.Init(pq)
+	// Create a priority queue, put the items in it, and
+	// establish the priority queue (heap) invariants.
+	pq := make(PriorityQueue, len(items))
+	i := 0
 	for value, priority := range items {
-		item := &Item{
+		pq[i] = &Item{
 			value:    value,
 			priority: priority,
+			index:    i,
 		}
-		heap.Push(pq, item)
+		i++
 	}
+	heap.Init(&pq)
 
 	// Insert a new item and then modify its priority.
 	item := &Item{
 		value:    "orange",
 		priority: 1,
 	}
-	heap.Push(pq, item)
+	heap.Push(&pq, item)
 	pq.update(item, item.value, 5)
 
 	// Take the items out; they arrive in decreasing priority order.
 	for pq.Len() > 0 {
-		item := heap.Pop(pq).(*Item)
+		item := heap.Pop(&pq).(*Item)
 		fmt.Printf("%.2d:%s ", item.priority, item.value)
 	}
 	// Output:
diff --git a/src/pkg/container/heap/heap.go b/src/pkg/container/heap/heap.go
index 52c8507b4..c467a1191 100644
--- a/src/pkg/container/heap/heap.go
+++ b/src/pkg/container/heap/heap.go
@@ -22,7 +22,7 @@ import "sort"
 // min-heap with the following invariants (established after
 // Init has been called or if the data is empty or sorted):
 //
-//	!h.Less(j, i) for 0 <= i < h.Len() and j = 2*i+1 or 2*i+2 and j < h.Len()
+//	!h.Less(j, i) for 0 <= i < h.Len() and 2*i+1 <= j <= 2*i+2 and j < h.Len()
 //
 // Note that Push and Pop in this interface are for package heap's
 // implementation to call.  To add and remove things from the heap,
@@ -78,7 +78,7 @@ func Remove(h Interface, i int) interface{} {
 	return h.Pop()
 }
 
-// Fix reestablishes the heap ordering after the element at index i has changed its value.
+// Fix re-establishes the heap ordering after the element at index i has changed its value.
 // Changing the value of the element at index i and then calling Fix is equivalent to,
 // but less expensive than, calling Remove(h, i) followed by a Push of the new value.
 // The complexity is O(log(n)) where n = h.Len().