infinity cycle fix

code/__HELPERS/data_struct/priority_queue.dm

@@ -1,34 +1,48 @@
 /priority_queue
-    var/list/heap = list()
+	var/list/priority_node/heap = list()
 
-/priority_queue/proc/enqueue(value, priority)
-    heap += list(list(priority, value))
-    bubble_up(heap.len)
+/priority_node
+	var/item
+	var/priority
 
-/priority_queue/proc/dequeue()
-    if (heap.len == 0)
-        return null
+/priority_node/New(item, priority)
+	. = ..()
+	src.item = item
+	src.priority = priority
 
-    var/list/top = heap[1]
-    heap[1] = heap[heap.len]
-    heap.Cut(heap.len, heap.len)
-    bubble_down(1)
+/priority_queue/proc/enqueue(value, priority)
+	heap += list(new /priority_node(value, priority))
+	bubble_up(heap.len)
 
-    return top[2]
+/priority_queue/proc/dequeue()
+	if (heap.len == 0)
+		return null
+
+	var/priority_node/top = heap[1]
+	var/bottom = heap[heap.len]
+	var/item = top.item
+	heap -= bottom
+	if(!heap.len)
+		qdel(top)
+		return item
+	heap[1] = bottom
+	bubble_down(1)
+	qdel(top)
+	return item
 
 /priority_queue/proc/peek()
-    if (heap.len == 0)
-        return null
-    return heap[1][2]
+	if (heap.len == 0)
+		return null
+	return heap[1].item
 
 /priority_queue/proc/is_empty()
-    return heap.len == 0
+	return heap.len == 0
 
 /priority_queue/proc/bubble_up(index)
 	while(index > 1)
 		var/parent = round(index / 2)
 
-		if (heap[parent][1] < heap[index][1])
+		if (heap[parent].priority < heap[index].priority)
 			break
 
 		swap(index, parent)
@@ -39,10 +53,10 @@
 	while(index * 2 <= heap.len)
 		var/child = index * 2
 
-		if (child + 1 <= heap.len && heap[child + 1][1] < heap[child][1])
+		if (child + 1 <= heap.len && heap[child + 1].priority < heap[child].priority)
 			child++
 
-		if (heap[index][1] < heap[child][1])
+		if (heap[index].priority < heap[child].priority)
 			break
 
 		swap(index, child)