sync-or-async

Write JavaScript code that can be both synchronous and asynchronous.

Get it with npm i sync-or-async.

Example

const {sync, async} = require('sync-or-async');

const
  getPartialSums
  = function*(arr)
    { const partialSums = [];
      let sum = 0;

      for (const n of arr)
        partialSums.push(sum += yield n); // yield n to possibly await it.

      return partialSums;};

console.log(sync(getPartialSums([1, 2, 3, 4]))); // [1, 3, 6, 10]

async(getPartialSums([1, 2, 3, 4].map(n => Promise.resolve(n))))
.then(console.log); // [1, 3, 6, 10]

API

const {sync, async} = require('sync-or-async');

sync(iter, value)

• iter is an Iterator
• value can be anything

Iterates through iter. The argument to each iter.next call is the .value of the previous IteratorResult, except that value is passed initially. The .value of the final IteratorResult is returned.

async(iter, value)

• iter is an Iterator
• value can be anything
• Returns a Promise

Iterates through iter. The argument to each iter.next call is the awaited .value of the previous IteratorResult, except that value is passed initially. A Promise resolving to the .value of the final IteratorResult is returned.