An iterator abstraction for async operations
npm install async-iterablebash
npm install --save async-iterable
`
Usage (ES6 + modules + async/await)
`javascript
import AsyncIterable from 'async-iterable'
// Create an infinite number generator (for the iteration seed)
function* infiniteNumGen() {
var index = 0
while (true)
yield index++
}
// Create the AsyncIterable.
// note that defining an AsyncIterator is an immediate sync operation,
// none of the callbacks below will be called before it is iterated
let repoNamesEndingWithJsAsyncIterable = new AsyncIterable(infiniteNumGen())
// (you can define sync or async data transformations)
.map(async (n) => {
let res = await axios.get(https://api.github.com/repositories?since=${n})
return res.data[0].name
})
// (you can define sync or async data filters)
.filter((name) => name.endsWith('js'))
// (you can define max items count)
.take(1000000)
// Iterate the AsyncIterator.
let firstMillionJsGithubRepoNames = new Set()
await repoNamesEndingWithJsAsyncIterable.forEach((name) => {
// requests will fire here, one before each iteration
firstMillionJsGithubRepoNames.add(name)
})
`
Usage (ES6 + modules + async/await + babel-plugin-transform-async-generator-functions)
AsyncIterable is also iterable via the new tc39 async-iteration proposal syntex
(for now, the babel plugin 'babel-plugin-transform-async-generator-functions' is required to support this syntex)
`javascript
import AsyncIterable from 'async-iterable'
// Create the AsyncIterable.
let repoNamesEndingWithJsAsyncIterable = new AsyncIterable([1, 2, 3])
.map(async (n) => {
let res = await axios.get(https://api.github.com/repositories?since=${n})
return res.data[0].name
})
// Iterate the AsyncIterator using the tc39 async-iteration proposal syntex
for await (const name of repoNamesEndingWithJsAsyncIterable) {
console.log(name);
}
``