Removed priorityQueue (unused)

regex/priorityQueue.go

@@ -1,89 +0,0 @@
-package regex
-
-import "container/heap"
-
-// Implement a priority queue using container/heap
-
-const (
-	min_priority int = iota
-	zerostate_priority
-	alternation_priority
-	kleene_priority
-	char_priority
-	max_priority
-)
-
-func getPriority(state *nfaState) int {
-	if state.isKleene {
-		return zerostate_priority
-	} else if state.isAlternation {
-		return alternation_priority
-	} else {
-		if state.isEmpty {
-			return zerostate_priority
-		} else {
-			return char_priority
-		}
-	}
-}
-
-type priorQueueItem struct {
-	state    *nfaState
-	priority int
-	index    int
-}
-
-func newPriorQueueItem(state *nfaState) *priorQueueItem {
-	return &priorQueueItem{
-		state:    state,
-		index:    -1,
-		priority: getPriority(state),
-	}
-}
-
-type priorityQueue []*priorQueueItem
-
-func (pq priorityQueue) Len() int {
-	return len(pq)
-}
-
-func (pq priorityQueue) Less(i, j int) bool {
-	if pq[i].priority == pq[j].priority {
-		return pq[i].index < pq[j].index
-	}
-	return pq[i].priority > pq[j].priority // We want max-heap, so we use greater-than
-}
-
-func (pq priorityQueue) Swap(i, j int) {
-	pq[i], pq[j] = pq[j], pq[i]
-	pq[i].index = i
-	pq[j].index = j
-}
-
-func (pq *priorityQueue) Push(x any) {
-	length := len(*pq)
-	item := x.(*priorQueueItem)
-	item.index = length
-	*pq = append(*pq, item)
-}
-
-func (pq *priorityQueue) Pop() any {
-	old := *pq
-	n := len(old)
-	item := old[n-1]
-	old[n-1] = nil
-	item.index = -1
-	*pq = old[0 : n-1]
-	return item
-}
-func (pq *priorityQueue) peek() any {
-	queue := *pq
-	n := len(queue)
-	return queue[n-1]
-}
-
-func (pq *priorityQueue) update(item *priorQueueItem, value *nfaState, priority int) {
-	item.state = value
-	item.priority = priority
-	heap.Fix(pq, item.index)
-}