map

map :: (Function mapper, Collection collection) => Collection | Promise<Collection>

description

Iterates over a collection (Array, Object, Map, Set) and returns a new collection of the same type containing each value from the input collection after it has been transformed by the provided mapper function.

Like many Collection methods in Conductor, map works with both asynchronous & synchronous mappers. If you use a synchronous mapper, map will work like Array.prototype.map and return a Collection synchronously.

const values = [0, 2, 4]
const double = x => 2 * x
map(double, values) // [0, 4, 8]

If you use an asynchronous mapper, map will return a Promise, and you will need to use await or Promise.prototype.then to retrieve the new collection.

const values = [0, 2, 4]
const double = async x => 2 * x
map(double, values) // Promise<Pending>
await map(double, values) // [0, 4, 8]

Important

If you use an asynchronous mapper, all mapper calls will be done in parallel, but the input collection's order will be preserved.