Move an async function into its own thread.
A simplified single-function version of workerize.
The name is somewhat of a poor choice, but it was available on npm.
Greenlet only supports browser environments, since it uses Web Workers. For use in a NodeJS environment, Web Workers must be polyfilled using a library like node-webworker.
npm i -S greenletAccepts an async function with, produces a copy of it that runs within a Web Worker.
⚠️ Caveat: the function you pass cannot rely on its surrounding scope, since it is executed in an isolated context.
greenlet(Function) -> Function
Greenlet is most effective when the work being done has relatively small inputs/outputs.
One such example would be fetching a network resource when only a subset of the resulting information is needed:
import greenlet from 'greenlet'
let getName = greenlet( async username => {
let url = `https://api.github.com/users/${username}`
let res = await fetch(url)
let profile = await res.json()
return profile.name
})
console.log(await getName('developit'))🔄 Run this example on JSFiddle
Thankfully, Web Workers have been around for a while and are broadly supported by Chrome, Firefox, Safari, Edge, and Internet Explorer 10+.
If you still need to support older browsers, you can just check for the presence of window.Worker:
if (window.Worker) {
...
} else {
...
}In addition to the contributors, credit goes to @sgb-io for his annotated exploration of Greenlet's source. This prompted a refactor that clarified the code and allowed for further size optimizations.