Sweet Collections

Typescript implementations of in-memory cache data-structures for Node and Browser. These data-structures are:

• LruMap: A fixed size Map which removes the least recently used entry.
• LruSet: A fixed size Set which removes the least recently used entry. (Backed by a LruMap)
• LfuMap: A fixed size Map which removes the least frequently used entry.
• LfuSet: A fixed size Set which removes the least frequently used entry. (Backed by a LfuMap)
• SortedArray: An Array that stays sorted after any modification.
• SortedMap: A Map with entries stays sorted by key after any modification. (Backed by a SortedArray)
• SortedSet: A Set with entries stays sorted after any modification. (Backed by a SortedArray)
• Heap: A collection that have always the largest, smallest or most relevant value on top.
• Stack: A collection that have always the last added value on top.
• Queue: A collection that have always the first added value on top.

Install

npm install --save sweet-collections

or

yarn add sweet-collections

Usage

LruMap

import { LruMap } from 'sweet-collections';

const map = new LruMap<number, number>(3);
map.set(1, 1);
map.set(2, 2);
map.set(3, 3);              // least recent used: 1
console.log(map.has(1))     // true, least recent used: 2
console.log(map.get(2))     // 1, least recent used: 3

map.set(4, 4);
console.log(map.has(3))     // false
console.log(map.get(3))     // undefined

console.log(map.isFull())   // true
map.delete(1);
console.log(map.size)       // 2

map.clear();
console.log(map.size)       // 0

LruSet

import { LruSet } from 'sweet-collections';

const set = new LruSet<number>(3);
set.add(1);
set.add(2);
set.add(3);                 // least recent used: 1
console.log(set.has(1))     // true, least recent used: 2

set.add(4);
console.log(set.has(2))     // false

console.log(set.isFull())   // true
set.delete(1);
console.log(set.size)       // 2

set.clear();
console.log(set.size)       // 0

LfuMap

import { LfuMap } from 'sweet-collections';

const map = new LfuMap<number, number>(3);
map.set(1, 1);
map.set(2, 2);
map.set(3, 3);              // least frequently used: 1
console.log(map.has(1))     // true, least frequently used: 2
console.log(map.get(2))     // 1, least frequently used: 3

map.set(4, 4);
console.log(map.has(3))     // false
console.log(map.get(3))     // undefined

console.log(map.isFull())   // true
map.delete(1);
console.log(map.size)       // 2

map.clear();
console.log(map.size)       // 0

LfuSet

import { LfuSet } from 'sweet-collections';

const set = new LfuSet<number>(3);
set.add(1);
set.add(2);
set.add(3);                 // least frequently used: 1
console.log(set.has(1))     // true, least frequently used: 2
console.log(set.has(2))     // true, least frequently used: 3

set.add(4);
console.log(set.has(3))     // false

console.log(set.isFull())   // true
set.delete(1);
console.log(set.size)       // 2

set.clear();
console.log(set.size)       // 0

SortedArray

import { SortedArray } from 'sweet-collections';

// Increasing order sorted array
const array = new SortedArray<number>((a: number, b: number) => a - b);
array.push(4);
array.push(1);
array.push(2);
array.push(3);
array.push(5);
console.log(array.toArray());       // [1, 2, 3, 4, 5]
console.log(array.get(2));          // 3
console.log(array.get(4));          // 5
console.log(array.length);          // 5

array.delete(4);
console.log(array.toArray());       // [1, 2, 3, 5]
console.log(array.includes(4));     // false

array.push(1);
console.log(array.toArray());       // [1, 1, 2, 3, 5]
console.log(array.count(1));        // 2
console.log(array.firstIndexOf(1)); // 0
console.log(array.lastIndexOf(1));  // 1

console.log(array.shift());         // 1
console.log(array.pop());           // 1
console.log(array.min());           // 1
console.log(array.max());           // 3
console.log(array.toArray());       // [1, 2, 3]

SortedMap

import { SortedMap } from 'sweet-collections';

// Increasing order sorted map
const map = new SortedMap<number, string>((a: number, b: number) => a - b);
map.set(3, 'c');
map.set(2, 'd');
map.set(5, 'a');
map.set(4, 'b');
map.set(1, 'e');
console.log([...map.keys()]);       // [1, 2, 3, 4, 5]
console.log([...map.values()]);     // ["e", "d", "c", "b", "a"]
console.log(map.get(2));            // "d"
console.log(map.get(4));            // "b"
console.log(map.size);              // 5

map.delete(4);
console.log([...map.keys()]);       // [1, 2, 3, 5]
console.log([...map.values()]);     // ["e", "d", "c", "a"]
console.log(map.has(4));            // false

SortedSet

import { SortedSet } from 'sweet-collections';

// Increasing order sorted set
const set = new SortedSet<number>((a: number, b: number) => a - b);
set.add(3);
set.add(2);
set.add(5);
set.add(4);
set.add(1);
console.log([...set.keys()]);       // [1, 2, 3, 4, 5]
console.log(set.has(2));            // true
console.log(set.has(4));            // true
console.log(set.size);              // 5

set.delete(4);
console.log([...set.keys()]);       // [1, 2, 3, 5]
console.log(set.has(4));            // false

Heap

import { Heap } from 'sweet-collections';

// Heap with the maximum value on top
const heap = new Heap<number>((a: number, b: number) => a > b);
heap.push(3);
heap.push(2);
heap.push(5);
heap.push(4);
heap.push(1);
console.log(heap.peek());        // 5
console.log(heap.pop());         // 5
console.log(heap.peek());        // 4
console.log(heap.replace(0));    // 4
console.log(heap.peek());        // 3

Stack

import { Stack } from 'sweet-collections';

const stack = new Stack<number>();
stack.push(3);
stack.push(2);
console.log(stack.top());         // 2
stack.push(5, 4, 1);
console.log(stack.pop());         // 1
console.log(stack.top());         // 4
console.log(stack.size);          // 4

Queue

import { Queue } from 'sweet-collections';

const queue = new Queue<number>();
queue.push(3);
queue.push(2);
console.log(queue.pop());         // 3
queue.push(5, 4, 1);
console.log(queue.pop());         // 2
console.log(queue.peek());        // 5
console.log(queue.size);          // 3

Author

👤 Nasreddine Bac Ali

• Website: nasreddinebacali.info
• Github: @bacali95
• LinkedIn: @bacali

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📝 License

Copyright © 2021 Nasreddine Bac Ali. This project is ISC licensed.