Reducer.count | /mod.ts | rimbu@0.13.1

Rimbu is a TypeScript library focused on immutable, performant, and type-safe collections and other tools.

actor base bimap bimultimap collection-types common core deep graph hashed list multimap multiset ordered sorted spy stream table typical

mod.ts (default module)

ArrowGraph

ArrowGraphHashed

ArrowGraphSorted

ArrowValuedGraph

ArrowValuedGraphHashed

ArrowValuedGraphSorted

EdgeValuedGraphHashed

EdgeValuedGraphSorted

HashMultiMapHashValue

HashMultiMapSortedValue

HashMultiSet

HashSet

HashTableHashColumn

HashTableSortedColumn

SortedMultiMapHashValue

SortedMultiMapSortedValue

SortedMultiSet

SortedSet

SortedTableHashColumn

SortedTableSortedColumn

variable Reducer.count

import { Reducer } from "https://deno.land/x/rimbu@0.13.1/mod.ts";
const { count } = Reducer;

Returns a Reducer that remembers the amount of input items provided.

Examples

Example 1

const stream = Stream.range({ amount: 10 })
console.log(stream.reduce(Reducer.count()))
// => 10
console.log(stream.reduce(Reducer.count(v => v < 5)))
// => 5

type

{ (): Reducer<never, number>; <T>(pred: (value: T, index: number) => boolean): Reducer<T, number>; }