Function take

Take a specific number of items from the front sequence and drop the rest.

import { pipe } from "yta"
import { take, toArray } from "yta/async";
import { asAsync, range } from "yta/sync";

await pipe(range(15), toAsync(), take(5), toArray());
// => [0, 1, 2, 3, 4]
Copy

If the number is negative take the last n numbers of the sequence, which is effectively the same as drop(length - n) if you know the length of the length of the iterator.

Note: Asking for the last items in an async iterator requires the whole iteration to finish before we emit the first item. This will create a lag between when the item was first emitted until it will pass through this operator.

import { pipe } from "yta"
import { take, toArray } from "yta/async";
import { asAsync, range } from "yta/sync";

await pipe(range(15) asAsync(), take(-5), toArray());
// => [10, 11, 12, 13, 14]
Copy

Note: because the length of the iterator is not known—if you use negative index the entire iterator has to be consumed before yielding the first item. This can result in an infinite loop if the iterator is indefinite.

See also:

• slice
• take
• takeWhile