concurrent() function

Concurrent is used to balance the load of multiple asynchronous requests. The first argument receives a number that controls the number of loads, and the second argument is an AsyncIterable. See toAsync to create an AsyncIterable .

Signature:

declare function concurrent<A>(length: number, iterable: AsyncIterable<A>): AsyncIterableIterator<A>;

Example

await pipe(
  [1, 2, 3, 4, 5, 6],
  toAsync,
  map((a) => delay(1000, a)),
  concurrent(3),
  each(console.log), // log 1, 2, 3, 4, 5, 6
); // 2 seconds

// evaluation
//              ┌─────┐  ┌─────┐  ┌─────┐  ┌─────┐  ┌─────┐  ┌─────┐
//              │  1  │──│  2  │──│  3  │──│  4  │──│  5  │──│  6  │
//              └──┬──┘  └──┬──┘  └──┬──┘  └──┬──┘  └──┬──┘  └──┬──┘
//      map        │        │        │        │        │        │
// concurrent(3)  (1)      (1)      (1)      (2)      (2)      (2)
//                 │        │        │        │        │        │
//                 ▼        ▼        ▼        ▼        ▼        ▼

await pipe(
  [1, 2, 3, 4, 5, 6],
  toAsync,
  map((a) => delay(1000, a)),
  each(console.log), // log 1, 2, 3, 4, 5, 6
); // 6 seconds

// evaluation
//              ┌─────┐  ┌─────┐  ┌─────┐  ┌─────┐  ┌─────┐  ┌─────┐
//              │  1  │──│  2  │──│  3  │──│  4  │──│  5  │──│  6  │
//              └──┬──┘  └──┬──┘  └──┬──┘  └──┬──┘  └──┬──┘  └──┬──┘
//      map        │        │        │        │        │        │
//                (1)      (2)      (3)      (4)      (5)      (6)
//                 │        │        │        │        │        │
//                 ▼        ▼        ▼        ▼        ▼        ▼

Try It

see pipe, toAsync, toArray each, map

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