What is setimmediate?
The setimmediate npm package is a simple and lightweight implementation of the setImmediate API, which is designed to execute a function once the current event loop tick is complete. It is a polyfill for the setImmediate function that is not available in all JavaScript environments, such as older browsers or certain Node.js versions.
What are setimmediate's main functionalities?
Scheduling functions to run after the current event loop tick
This feature allows you to schedule a function to be executed after the current event loop tick has finished. It is useful for deferring execution without using setTimeout with a delay of 0.
require('setimmediate');
setImmediate(() => {
console.log('This will run after the current event loop tick.');
});
Clearing a scheduled immediate
This feature provides the ability to cancel a scheduled immediate, preventing the function from being executed if it has not already been called.
require('setimmediate');
const handle = setImmediate(() => {
console.log('This will not run.');
});
clearImmediate(handle);
Other packages similar to setimmediate
bluebird
Bluebird is a comprehensive promise library that includes a utility for deferring functions similar to setImmediate. It provides a method called .defer() which can be used to schedule tasks to run in the future. Bluebird's implementation may differ in terms of performance and timing guarantees.
asap
The asap package is a task scheduler that prioritizes tasks in a way that, like setImmediate, they run after the current call stack but with different internal mechanisms. It aims to execute tasks as soon as possible while being faster than setTimeout or setImmediate in some cases.