@datastructures-js/priority-queue - npm Package Compare versions

Comparing version 4.0.0 to 4.1.0

CHANGELOG.md

@@ -9,2 +9,6 @@ # Changelog
 
+## [4.1.0] - 2020-04-22
+### Added
+- allow passing a priority callback in constructor.
+
 ## [4.0.0] - 2020-04-13
@@ -11,0 +15,0 @@ ### Changed

package.json

 {
   "name": "@datastructures-js/priority-queue",
-  "version": "4.0.0",
+  "version": "4.1.0",
   "description": "priority queue implementation in javascript using a Min Heap",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

@@ -48,12 +48,15 @@ # @datastructures-js/priority-queue
 ### Construction
+The constructor can accept a callback to get the priority from the queued element. If not passed, the priortiy should be passed with `.enqueue`.
 
 #### Example
 ```js
+// the priority not part of the enqueued element
 const patientsQueue = new MinPriorityQueue();
 
-const biddersQueue = new MaxPriorityQueue();
+// the priority is a prop of the queued element
+const biddersQueue = new MaxPriorityQueue({ priority: (bid) => bid.value });
 ```
 
 ### .enqueue(element, priority)
-adds an element with a priority (number) to the queue.
+adds an element with a priority (number) to the queue. Priority is not required here if a priority callback has been defined in the constructor. If passed here in addition to an existing constructor callback, it will override the callback one.
 
@@ -85,7 +88,7 @@ <table>
 
-// MaxPriorityQueue Example, where priority is the bid for example
-biddersQueue.enqueue('bidder y', 1000); // lowest priority
-biddersQueue.enqueue('bidder w', 2500);
-biddersQueue.enqueue('bidder z', 3500); // highest priority
-biddersQueue.enqueue('bidder x', 3000);
+// MaxPriorityQueue Example, where priority is the bid for example. Priority is obtained from the callback.
+biddersQueue.enqueue({ name: 'bidder y', value: 1000 }); // lowest priority
+biddersQueue.enqueue({ name: 'bidder w', value: 2500 });
+biddersQueue.enqueue({ name: 'bidder z', value: 3500 }); // highest priority
+biddersQueue.enqueue({ name: 'bidder x', value: 3000 });
 ```
@@ -118,3 +121,3 @@
 
-console.log(biddersQueue.front()); // { priority: 3500, element: 'bidder z' }
+console.log(biddersQueue.front()); // { priority: 3500, element: { name: 'bidder z', value: 3500 } }
 ```
@@ -133,3 +136,2 @@
 
-
 <table>
@@ -151,5 +153,5 @@ <tr>
 
-biddersQueue.enqueue('bidder m', 1000); // lowest priority
-biddersQueue.enqueue('bidder c', 1000); // lowest priority
-console.log(biddersQueue.back()); // { priority: 1000, element: 'bidder y' }
+biddersQueue.enqueue({ name: 'bidder m', value: 1000 }); // lowest priority
+biddersQueue.enqueue({ name: 'bidder c', value: 1000 }); // lowest priority
+console.log(biddersQueue.back()); // { priority: 1000, element: { name: 'bidder y', value: 1000 } }
 ```
@@ -183,4 +185,4 @@
 
-console.log(biddersQueue.dequeue()); // { priority: 3500, element: 'bidder z' }
-console.log(biddersQueue.front()); // { priority: 3000, element: 'bidder x' }
+console.log(biddersQueue.dequeue()); // { priority: 3500, element: { name: 'bidder z', value: 3500 } }
+console.log(biddersQueue.front()); // { priority: 3000, element: { name: 'bidder x', value: 3000 } }
 ```
@@ -278,7 +280,7 @@
 [
-  { priority: 3000, element: 'bidder x' },
-  { priority: 2500, element: 'bidder w' },
-  { priority: 1000, element: 'bidder y' },
-  { priority: 1000, element: 'bidder m' },
-  { priority: 1000, element: 'bidder c' }
+  { priority: 3000, element: { name: 'bidder x', value: 3000 } },
+  { priority: 2500, element: { name: 'bidder w', value: 2500 } },
+  { priority: 1000, element: { name: 'bidder y', value: 1000 } },
+  { priority: 1000, element: { name: 'bidder m', value: 1000 } },
+  { priority: 1000, element: { name: 'bidder c', value: 1000 } }
 ]
@@ -285,0 +287,0 @@ */

src/maxPriorityQueue.js

@@ -15,4 +15,4 @@ /**
 class MaxPriorityQueue extends PriorityQueue {
-  constructor() {
-    super();
+  constructor(options) {
+    super(options);
     this._heap = new MaxHeap();
@@ -19,0 +19,0 @@ }

src/minPriorityQueue.js

@@ -15,4 +15,4 @@ /**
 class MinPriorityQueue extends PriorityQueue {
-  constructor() {
-    super();
+  constructor(options) {
+    super(options);
     this._heap = new MinHeap();
@@ -19,0 +19,0 @@ }

src/priorityQueue.js

@@ -12,2 +12,10 @@ /**
 class PriorityQueue {
+  constructor(options = {}) {
+    const { priority } = options;
+    if (priority !== undefined && typeof priority !== 'function') {
+      throw new Error('invalid priority callback');
+    }
+    this._getPriority = typeof priority === 'function' ? priority : null;
+  }
+
   /**
@@ -67,6 +75,11 @@ * @public
   enqueue(element, priority) {
-    if (Number.isNaN(+priority) || priority < 1) {
-      throw new Error('priority should be a positive none-zero number');
+    if (priority && (Number.isNaN(+priority) || priority < 1)) {
+      throw new Error('invalid priority number');
     }
-    this._heap.insert(priority, element);
+
+    if (!priority && this._getPriority === null) {
+      throw new Error('missing priority number or constructor callback');
+    }
+
+    this._heap.insert(priority || this._getPriority(element), element);
   }
@@ -73,0 +86,0 @@

No alert changes

Improved metrics

Total package byte prevSize

14193

increased by10.51%

Lines of code

146

increased by7.35%

Number of lines in readme file

316

increased by0.64%

No dependency changes