MapList

A much faster alternative to filter with similar API

Purpose

complexity of list.filter(...) is O(N). As the list grows, ther performance deteriorates. Fetching items from Map is fast as the complexity is O(1) but they don't have the convience of methods like filter, find and map. This library provides a way to convert a list to mapped list such that it is very fast like Map and has all utility methods.

Usage

CreateFrom

Convert a list/array of itemes as mapped list

const map = MapList.createFrom(dataFromSomeAPI);

Or, you can initialize

const map = new Map<number,string>([[1,"A"],[2,"B"]])

You can have objects too instead of this.

findAll

Finds all elements for specified IDs. You can also specify the property to be used as ID.

const mapSearchByKeys = map.findAll([101,103])

find

Finds first element and returns (undefined, if not found)

const searchedOne = map.find(x=>x.name == "D")

filter

Same as list filter. Pass a predicate to get filtered results.

const filtered = map.filter(m=>m.posts.some(p=>p.isPublished))