https://github.com/iwatakeshi/puchi

A JavaScript library to encode and decode large integer strings of base n to base 64.
https://github.com/iwatakeshi/puchi

Last synced: 6 days ago
JSON representation

A JavaScript library to encode and decode large integer strings of base n to base 64.

• Host: GitHub
• URL: https://github.com/iwatakeshi/puchi
• Owner: iwatakeshi
• License: mit
• Created: 2019-01-01T18:31:41.000Z (about 6 years ago)
• Default Branch: master
• Last Pushed: 2023-04-30T04:06:36.000Z (over 1 year ago)
• Last Synced: 2024-11-16T01:26:03.759Z (about 2 months ago)
• Language: JavaScript
• Size: 32.2 KB
• Stars: 1
• Watchers: 2
• Forks: 0
• Open Issues: 4
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Awesome Lists containing this project

README

        
# puchi

A small JavaScript library to encode and decode large integer strings of base `n <= 64` to base 64.

## About

Puchi is a small and simple library that allows you to convert large integer strings of base `n` to base 64. One use case would be to convert MongoDB's ObjectID (12-byte, base 16) to base 64 for a url-shortener.

It also allows you to convert non-integer strings of base `n` to base `n` using the `convert` function.

I'm not sure if that's all useful but it's there anyways :satisfied:. See below for an example.

> Note: This library depends on [big-integer](https://github.com/peterolson/BigInteger.js) to perform large integer calculations.

### `encode(value: string, base?: number = 16)`

* `value` - The integer string to encode.

* `base`  - The base or radix of the integer string.

```js

const { encode } = require('puchi')

console.log(encode("5c2bd2c156ddf30c73b39953")) // → n2LiMlrtYMNPIVBj

```

### `decode(value: string, base?: number = 16)`

* `value` - The integer string to decode.

* `base`  - The base or radix of the integer string.

```js

const { decode } = require('puchi')

console.log(decode("n2LiMlrtYMNPIVBj")) // → 5c2bd2c156ddf30c73b39953

```

### `convert(value: string, from!: number, to!: number, domain?: string[], range?: string[])`

* `value`  - The integer string to convert.

* `from`   - The base or radix of the integer string. (required)

* `to`     - The base or radix to convert to. (required)

* `domain` - The domain or character map. Defaults to an array of 64 characters: `[0-9, a-z, A-Z, '_', '-']`

* `range`  - The range or character map. Defaults to an array of 64 characters: `[0-9, a-z, A-Z, '_', '-']`

```js

const { convert } = require('puchi')

console.log(convert('12345', 10, 2)) // → 11000000111001

console.log(convert('11000000111001', 2, 10)) // → 12345

// Note: The following example does not output in the ASCII sense of binary

// but more of a theoretical mapping.

const domain = "abcdefghijklmnopqrstuvwxyz !".split('');

console.log(convert("hello world!", domain.length, 2, domain)) 

// → 11010010111000111010110000111100010001011010100111011111

const range = domain;

console.log(convert(

  "11010010111000111010110000111100010001011010100111011111",

  2, range.length, null, range))

// → hello world!

```