https://github.com/webreflection/indexed-values

An ever growing Set based utility to optimize JSON, IndexedDB, or postMessage.
https://github.com/webreflection/indexed-values

indexeddb json postmessage

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An ever growing Set based utility to optimize JSON, IndexedDB, or postMessage.

• Host: GitHub
• URL: https://github.com/webreflection/indexed-values
• Owner: WebReflection
• Created: 2021-09-07T08:40:01.000Z (over 3 years ago)
• Default Branch: main
• Last Pushed: 2021-09-22T08:55:24.000Z (over 3 years ago)
• Last Synced: 2024-12-31T15:24:57.258Z (5 months ago)
• Topics: indexeddb, json, postmessage
• Language: JavaScript
• Homepage: https://webreflection.medium.com/optimizing-json-indexeddb-or-postmessage-698112860899
• Size: 58.6 KB
• Stars: 21
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
# indexed-values

[![build status](https://github.com/WebReflection/indexed-values/actions/workflows/node.js.yml/badge.svg)](https://github.com/WebReflection/indexed-values/actions) [![Coverage Status](https://coveralls.io/repos/github/WebReflection/indexed-values/badge.svg?branch=main)](https://coveralls.io/github/WebReflection/indexed-values?branch=main)

**Social Media Photo by [Alexander Sinn](https://unsplash.com/@swimstaralex) on [Unsplash](https://unsplash.com/)**

[Related Blog Post](https://webreflection.medium.com/optimizing-json-indexeddb-or-postmessage-698112860899).

### Example

```js

import {IndexedValues} from 'indexed-values';

// create a Set of unique values

const main = new IndexedValues;

// derive a set

const sub1 = main.bindValues(["a", "b", "c"]);

const sub2 = main.bindValues(["a"]);

// derived sets can make the main Set grow

if (!sub2.has("d"))

  sub2.add("d");

// {"main":["a","b","c","d"],"data":[[0,1,2],[0,3]]}

console.log(JSON.stringify({

  main,

  data: [sub1, sub2]

}));

```

## API

The `IndexedValues` constructor extends the `Set` class, but it's a facade with the following peculiarities:

  * it is not posible to `delete` a single value, or `clear` the instance. `IndexedValues` instances are ever-growing

  * `.toJSON()` method returns an array of values held internally

  * `.valueOf()` method returns a real `Set` that can resist `postMessage`, or be stored directly as `IndexedDB`

  * `.bindValues(values = [])` returns a `Set` that can contain, add, or remove, any value. Added values will be reflected in the `IndexedValues` instance that created the bound `Set`.

  * `.bindIndexes(indexes = [])` is like `.bindValues()` but uses indexes instead, to initialize the derived `Set`. This is mostly useful for revival.

  * `.mapKeys(entries = [])` returns a `Map` where *keys* are derived from the `IndexedValues`. Added keys that are not known in the `IndexedValues` source, will be automatically added as part of the `Set`. Once serialized as *JSON*, these maps will represent all keys as indexes, because indeed these maps never hold keys as values, these hold keys as indexes.

  * `.mapEntries(entries = [])` is the revival counter-part of `.mapKeys()`. It returns a *map* with keys revived from the `IndexedValues` instance.

  * `.fromIndexes(indexes)` can revive right away `Set` instances, upgrading their prototype. This is a *quick and dirty* `.bindIndexes()` equivalent, available for performance reasons.

  * `.fromEntries(entries)` can revive right away `Map` instances, upgrading their prototype. This is a *quick and dirty* `.mapEntries()` equivalent, available for performance reasons.