union

• CodeSandbox Demo 1
• CodeSandbox Demo 2

Take a set of async iterations and turn them into an array of the latest values for that iterator.

This is the general function signature to achieve this:

export type Input<T> = AsyncIterable<T> | Iterable<T>;
export type UnionInput<T> = Input<Input<T>>;
export async function *union<T>(input: UnionInput<T>): AsyncIterable<(T | undefined)[]> {

This allows us to take multiple functions producing values and group an update set together.

import { union } from "@virtualstate/union";

for await (const set of union([[1, 2, 3, 4], [5, 6, 7, 8, 9]])) {
    console.log(set);
}

The above logs:

[ 1, 5 ]
[ 2, 6 ]
[ 3, 7 ]
[ 4, 8 ]
[ 4, 9 ]