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Enum

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

Version vom 03.11.2019. Aktuellste Version

Dieses Skript sollte nicht direkt installiert werden. Es handelt sich hier um eine Bibliothek für andere Skripte, welche über folgenden Befehl in den Metadaten eines Skriptes eingebunden wird // @require https://update.greasyfork.org/scripts/391854/746195/Enum.js 

// ==UserScript==
// @name         Enum
// @namespace    hoehleg.userscripts.private
// @version      0.2
// @description  Enumeration class. Each enum propertiy has the properties "ordinal", "name" and "text".
// @author       Gerrit Höhle
// @grant        none
// ==/UserScript==

/* jslint esnext: true */
const Enum = (() => {
    const initializing = Symbol("initializing");

    const createEnumInstance = (enumClass, name, ordinal, text = "") => {
        text = String(text);
        return Object.assign(new enumClass(initializing), {
            get ordinal() { return ordinal; },
            get name() { return name; },
            get text() { return text; },
        });
    };

    return class EnumBase {

        constructor(processIndicator) {
            if (processIndicator !== initializing) {
                throw TypeError("Instantiation of abstract enum class");
            }
        }

        valueOf() { return this.ordinal; }

        toString() { return this.text || this.name; }

        static init(enumDef = [], firstOrdinal = 0, ordinalSupplier = previousOrdinal => previousOrdinal + 1) {
            if (Object.isFrozen(this)) {
                throw TypeError("Reinitialization of finalized enum class");
            }

            let ordinal;
            const ordinals = [];
            for (let enumDefObj of (Array.isArray(enumDef) ? enumDef : [ enumDef ])) {
                if (typeof enumDefObj !== 'object') {
                    enumDefObj = { [enumDefObj]: "" };

                }
                for (let [name, text] of Object.entries(enumDefObj)) {
                    ordinal = Number.parseInt((typeof ordinal === "undefined") ? firstOrdinal : ordinalSupplier(ordinal));
                    console.assert(typeof this[name] === "undefined", `duplicate enum [${name}]`);
                    console.assert(typeof this[ordinal] === "undefined", `duplicate ordinal [${ordinal}] for enum [${name}]`);

                    ordinals.push(ordinal);

                    this[name] = createEnumInstance(this, name, ordinal, text);
                    Object.defineProperty(this, ordinal, { value: this[name] });
                }
            }

            const enums = ordinals.sort().map(ordinal => this[ordinal]);
            Object.defineProperty(this, Symbol.iterator, { value: () => enums[Symbol.iterator]() });

            return Object.freeze(this);
        }
    };
})();