each.js

This package is a foreach implementation of parallel, series and concurrent execution with promises.

$3

- each.parallel(iterator, cb)
- each.series(iterator, cb)
- each.concurrent(iterator, cb, concurrency)

iterator - Iterator to loop through.

cb - async (item, index, iterator) => {} - handler for iterator items.

concurrency - Number of parallel executed cb's in series.

All 3 functions: paralel, series and concurrent return promise which resolve to an array with all cb returned values.

Error handling: If one of cb functions throws then each function throws too.

$3

``sh
npm i -S each.js
`

$3

`js
const each = require('each.js');

// array
const array = [1, 2, 3, 4, 5];

// iterator (using generator function)
function* iterator() {
yield 1;
yield 2;
yield 3;
yield 4;
yield 5;
}

// timeout promise
const timeoutPromise = timeout => new Promise((resolve, reject) => {
setTimeout(() => {
resolve(timeout);
}, timeout);
});

// examples
// work both with arrays and iterators
(async () => {
// parallel
console.log('parallel');
const result1 = await each.parallel(iterator(), async (item, index) => {
console.log(item);
await timeoutPromise(1000);
return item;
});
console.log(result1);

// series
console.log('series');
const result2 = await each.series(array, async (item, index) => {
console.log(item);
await timeoutPromise(1000);
return item;
});
console.log(result2);

// concurrent
console.log('concurrent');
const result3 = await each.concurrent(iterator(), async (item, index) => {
console.log(item);
await timeoutPromise(1000);
return item;
}, 2);
console.log(result3);
})();
``