GeneratorFunction

GeneratorFunction constructor создаёт новый generator function объект. В JavaScript каждая функция-генератор - это фактически GeneratorFunction объект.

Обратите внимание, что GeneratorFunction - это не глобальный объект. Он может быть получен при выполнении следующего кода.

js

Object.getPrototypeOf(function* () {}).constructor;

Синтаксис

new GeneratorFunction ([arg1[, arg2[, ...argN]],] functionBody)

Параметры

arg1, arg2, ... argN

Имена, используемые функцией как имена формальных аргументов. Каждый должен быть строкой, которая соответствует правильному JavaScript идентификатору или списком таких строк, разделённых запятыми; например "x", "theValue", или "a,b".

functionBody

A string containing the JavaScript statements comprising the function definition.

Description

generator function objects created with the GeneratorFunction constructor are parsed when the function is created. This is less efficient than declaring a generator function with a function* expression and calling it within your code, because such functions are parsed with the rest of the code.

All arguments passed to the function are treated as the names of the identifiers of the parameters in the function to be created, in the order in which they are passed.

Примечание: generator function created with the GeneratorFunction constructor do not create closures to their creation contexts; they always are created in the global scope. When running them, they will only be able to access their own local variables and global ones, not the ones from the scope in which the GeneratorFunction constructor was called. This is different from using eval with code for a generator function expression.

Invoking the GeneratorFunction constructor as a function (without using the new operator) has the same effect as invoking it as a constructor.

Properties

GeneratorFunction.length

The GeneratorFunction constructor's length property whose value is 1.

GeneratorFunction.prototype (en-US)

Allows the addition of properties to all generator function objects.

GeneratorFunction prototype object

Properties

{{page('/en-US/docs/Web/JavaScript/Reference/Global_Objects/GeneratorFunction/prototype', 'Properties')}}

GeneratorFunction instances

GeneratorFunction instances inherit methods and properties from GeneratorFunction.prototype (en-US). As with all constructors, you can change the constructor's prototype object to make changes to all GeneratorFunction instances.

Examples

Creating a generator function from a GeneratorFunction constructor

js

var GeneratorFunction = Object.getPrototypeOf(function* () {}).constructor;
var g = new GeneratorFunction("a", "yield a * 2");
var iterator = g(10);
console.log(iterator.next().value); // 20

Specifications

Specification Status Comment
ECMAScript 2015 (6th Edition, ECMA-262)
Определение 'GeneratorFunction' в этой спецификации.		 Стандарт Initial definition.
ECMAScript (ECMA-262)
Определение 'GeneratorFunction' в этой спецификации.		 Живой стандарт

Browser compatibility

BCD tables only load in the browser

See also