ES6 module

Gruntfile.js

@@ -23,9 +23,21 @@ module.exports = function (grunt) {
 		},
 		copy: {
 			main: {
-				expand: true,
-				src: "tiny-lru.d.ts",
-				dest: "lib/"
+				files: [
+					{
+						expand: true,
+						src: "tiny-lru.d.ts",
+						dest: "lib/"
+					},
+					{
+						expand: true,
+						src: "src/lru.js",
+						dest: "lib/",
+						rename: function (dest) {
+							return dest + "tiny-lru.es6.js";
+						}
+					}
+				]
 			}
 		},
 		eslint: {

lib/tiny-lru.es6.js

@@ -0,0 +1,135 @@
+	class LRU {
+		constructor (max = 0, ttl = 0) {
+			this.first = null;
+			this.items = {};
+			this.last = null;
+			this.max = max;
+			this.size = 0;
+			this.ttl = ttl;
+		}
+
+		has (key) {
+			return key in this.items;
+		}
+
+		clear () {
+			this.first = null;
+			this.items = {};
+			this.last = null;
+			this.size = 0;
+
+			return this;
+		}
+
+		delete (key) {
+			if (this.has(key)) {
+				const item = this.items[key];
+
+				delete this.items[key];
+				this.size--;
+
+				if (item.prev !== null) {
+					item.prev.next = item.next;
+				}
+
+				if (item.next !== null) {
+					item.next.prev = item.prev;
+				}
+
+				if (this.first === item) {
+					this.first = item.next;
+				}
+
+				if (this.last === item) {
+					this.last = item.prev;
+				}
+			}
+
+			return this;
+		}
+
+		evict () {
+			const item = this.first;
+
+			delete this.items[item.key];
+			this.first = item.next;
+			this.first.prev = null;
+			this.size--;
+
+			return this;
+		}
+
+		get (key) {
+			let result;
+
+			if (this.has(key)) {
+				const item = this.items[key];
+
+				if (this.ttl > 0 && item.expiry <= new Date().getTime()) {
+					this.delete(key);
+				} else {
+					result = item.value;
+					this.set(key, result, true);
+				}
+			}
+
+			return result;
+		}
+
+		keys () {
+			return Object.keys(this.items);
+		}
+
+		set (key, value, bypass = false) {
+			let item;
+
+			if (bypass || this.has(key)) {
+				item = this.items[key];
+				item.value = value;
+
+				if (this.last !== item) {
+					const last = this.last,
+						next = item.next,
+						prev = item.prev;
+
+					if (this.first === item) {
+						this.first = item.next;
+					}
+
+					item.next = null;
+					item.prev = this.last;
+					last.next = item;
+
+					if (prev !== null) {
+						prev.next = next;
+					}
+
+					if (next !== null) {
+						next.prev = prev;
+					}
+				}
+			} else {
+				if (this.max > 0 && this.size === this.max) {
+					this.evict();
+				}
+
+				item = this.items[key] = {
+					expiry: this.ttl > 0 ? new Date().getTime() + this.ttl : this.ttl,
+					key: key,
+					prev: this.last,
+					next: null,
+					value
+				};
+
+				if (++this.size === 1) {
+					this.first = item;
+				} else {
+					this.last.next = item;
+				}
+			}
+
+			this.last = item;
+
+			return this;
+		}
+	}

package.json

@@ -13,6 +13,7 @@
   },
   "license": "BSD-3-Clause",
   "main": "lib/tiny-lru.js",
+  "module": "lib/tiny-lru.es6.js",
   "types": "lib/tiny-lru.d.ts",
   "engines": {
     "node": ">=6"