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Enum

Enumeration class. Each enum propertiy has the properties "ordinal", "name" and "text".

目前為 2019-11-03 提交的版本，檢視 最新版本。

此腳本不應該直接安裝，它是一個供其他腳本使用的函式庫。欲使用本函式庫，請在腳本 metadata 寫上： // @require https://update.cn-greasyfork.org/scripts/391854/746197/Enum.js 

  1. // ==UserScript==
  2. // @name         Enum
  3. // @namespace    hoehleg.userscripts.private
  4. // @version      0.2
  5. // @description  Enumeration class. Each enum propertiy has the properties "ordinal", "name" and "text".
  6. // @author       Gerrit Höhle
  7. // @grant        none
  8. // ==/UserScript==
  9.  
  10. /* jslint esnext: true */
  11. const Enum = (() => {
  12.     const initializing = Symbol("initializing");
  13.  
  14.     const createEnumInstance = (enumClass, name, ordinal, text = "") => {
  15.         text = String(text);
  16.         return Object.assign(new enumClass(initializing), {
  17.             get ordinal() { return ordinal; },
  18.             get name() { return name; },
  19.             get text() { return text; },
  20.         });
  21.     };
  22.  
  23.     return class EnumBase {
  24.  
  25.         constructor(processIndicator) {
  26.             if (processIndicator !== initializing) {
  27.                 throw TypeError("Instantiation of abstract enum class");
  28.             }
  29.         }
  30.  
  31.         valueOf() { return this.ordinal; }
  32.  
  33.         toString() { return this.text || this.name; }
  34.  
  35.         static init(enumDef = [], firstOrdinal = 0, ordinalSupplier = previousOrdinal => previousOrdinal + 1) {
  36.             if (Object.isFrozen(this)) {
  37.                 throw TypeError("Reinitialization of finalized enum class");
  38.             }
  39.  
  40.             let ordinal;
  41.             const ordinals = [];
  42.             for (let enumDefObj of (Array.isArray(enumDef) ? enumDef : [ enumDef ])) {
  43.                 if (typeof enumDefObj !== 'object') {
  44.                     enumDefObj = { [enumDefObj]: "" };
  45.  
  46.                 }
  47.                 for (let [name, text] of Object.entries(enumDefObj)) {
  48.                     ordinal = Number.parseInt((typeof ordinal === "undefined") ? firstOrdinal : ordinalSupplier(ordinal));
  49.                     console.assert(typeof this[name] === "undefined", `duplicate enum [${name}]`);
  50.                     console.assert(typeof this[ordinal] === "undefined", `duplicate ordinal [${ordinal}] for enum [${name}]`);
  51.  
  52.                     ordinals.push(ordinal);
  53.  
  54.                     this[name] = createEnumInstance(this, name, ordinal, text);
  55.                     Object.defineProperty(this, ordinal, { value: this[name] });
  56.                 }
  57.             }
  58.  
  59.             const enums = ordinals.sort().map(ordinal => this[ordinal]);
  60.             Object.defineProperty(this, Symbol.iterator, { value: () => enums[Symbol.iterator]() });
  61.  
  62.             return Object.freeze(this);
  63.         }
  64.     };
  65. })();