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xen-orchestra/@xen-orchestra/async-map/USAGE.md
Julien Fontanet 20377e9c56 feat(async-map): new implementations
These implementations are no longer compatible with plain objects but support iterables.

The previous implementation is still available as `@xen-orchestra/async-map/legacy`.
2021-03-01 16:55:06 +01:00

1.4 KiB

asyncMap(iterable, iteratee, thisArg = iterable)

Similar to Promise.all + Array#map for all iterables: calls iteratee for each item in iterable, and returns a promise of an array containing the awaited result of each calls to iteratee.

It rejects as soon as te first call to iteratee rejects.

import { asyncMap } from '@xen-orchestra/async-map'

const array = await asyncMap(iterable, iteratee, thisArg)

It can be used with any iterables (Array, Map, etc.):

const map = new Map()
map.set('foo', 42)
map.set('bar', 3.14)

const array = await asyncMap(map, async function ([key, value]) {
  // TODO: do async computation
  //
  // the map can be accessed via `this`
})

Use with plain objects

Plain objects are not iterable, but you can use Object.keys, Object.values or Object.entries to help:

const object = {
  foo: 42,
  bar: 3.14,
}

const array = await asyncMap(
  Object.entries(object),
  async function ([key, value]) {
    // TODO: do async computation
    //
    // the object can be accessed via `this` because it's been passed as third arg
  },
  object
)

asyncMapSettled(iterable, iteratee, thisArg = iterable)

Similar to asyncMap but waits for all promises to settle before rejecting.

import { asyncMapSettled } from '@xen-orchestra/async-map'

const array = await asyncMapSettled(iterable, iteratee, thisArg)