LazyAsync | /mod.ts | better_iterators@v1.5.0

method LazyAsync.prototype.groupBy

import { LazyAsync } from "https://deno.land/x/better_iterators@v1.5.0/mod.ts";

groupBy<Key>(keyFn: Transform<T, Key>): Promise<Map<Key, T[]>>

Given keyFn, use it to extract a key from each item, and create a Map grouping items by that key.

groupBy<Key, Value>(keyFn: Transform<T, Key>, valueFn: Transform<T, Value>): Promise<Map<Key, Value[]>>

Adds a valueFn to extract that value (instead of T) into a group.

Given keyFn, use it to extract a key from each item, and create a Map grouping items by that key.

Type Parameters

Key

Promise<Map<Key, T[]>>

Adds a valueFn to extract that value (instead of T) into a group.

Key

Value

Promise<Map<Key, Value[]>>