Deferred<T>

lang.Deferred

A small deferred helper: expose resolve / reject without writing new Promise((resolve, reject) => …).

Example

"nodejs";
const { Deferred } = require("lang");

async function main() {
  console.log(await add(1, 2));
}
main();

function add(a, b) {
  const d = new Deferred();
  setTimeout(() => {
    d.resolve(a + b);
  }, 1000);
  return d.promise();
}

Type parameters

Name
T

Table of contents

Constructors

• constructor

Accessors

• value

Methods

• promise
• reject
• resolve

Constructors

constructor

• new Deferred<T>(keepRunning?)

Type parameters

Name
T

Parameters

Name	Type	Default
keepRunning	boolean	true

Accessors

value

• get value(): undefined | T

The settled fulfilled value, or undefined while still pending or after rejection.

Returns

undefined | T

Methods

promise

▸ promise(): Promise<T>

Returns

Promise<T>

---

reject

▸ reject(reason?): boolean

Reject the underlying promise with reason. Returns false if the deferred was already settled.

Parameters

Name	Type
reason?	any

Returns

boolean

---

resolve

▸ resolve(value): boolean

Fulfill the underlying promise with value. Returns false if the deferred was already settled.

Parameters

Name	Type
value	T

Returns

boolean