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Enum

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

Fra 04.11.2019. Se den seneste versjonen.

Dette scriptet burde ikke installeres direkte. Det er et bibliotek for andre script å inkludere med det nye metadirektivet // @require https://update.greasyfork.org/scripts/391854/746693/Enum.js 

// ==UserScript==
// @name         Enum
// @namespace    hoehleg.userscripts.private
// @version      0.3
// @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");

    return class EnumBase {

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

            if (typeof text !== "undefined") {
                text = String(text);
            }

            Object.assign(this, {
                get ordinal() { return ordinal; },
                get name() { return name; },
                get text() { return text; }
            });
        }

        valueOf() { 
            return this.ordinal; 
        }

        toString() { 
            return (typeof this.text === "undefined") ? this.name : this.text;
        }

        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]: undefined };
                }
                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}]`);

                    this[name] = new this(initializing, { ordinal, name, text });
                    Object.defineProperty(this, ordinal, { 
                        value: this[name] 
                    });
                    
                    ordinals.push(ordinal);
                }
            }

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

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