https://github.com/dasch/crockford

An implementation of Crockford's base32 in Elm
https://github.com/dasch/crockford

Last synced: 24 days ago
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An implementation of Crockford's base32 in Elm

• Host: GitHub
• URL: https://github.com/dasch/crockford
• Owner: dasch
• License: apache-2.0
• Created: 2019-10-29T09:58:57.000Z (about 5 years ago)
• Default Branch: master
• Last Pushed: 2019-11-12T14:37:41.000Z (almost 5 years ago)
• Last Synced: 2023-08-08T20:39:03.741Z (about 1 year ago)
• Language: Elm
• Homepage: https://package.elm-lang.org/packages/dasch/crockford/latest/
• Size: 46.9 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 1
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# Crockford's base32 encoding in Elm

Encode integers as [Crockford-style base32 strings](https://www.crockford.com/base32.html).

From the specification:

> Base 32 is a textual 32-symbol notation for expressing numbers in a form that can be conveniently and accurately transmitted between humans and computer systems. It can be used for out of band communication of public keys.

>

> The encoding scheme is required to

>

>   - Be human readable and machine readable.

>   - Be compact. Humans have difficulty in manipulating long strings of arbitrary symbols.

>   - Be error resistant. Entering the symbols must not require keyboarding gymnastics.

>   - Be pronounceable. Humans should be able to accurately transmit the symbols to other humans using a telephone.

This package provides functions for encoding and decoding base32 data.

## Examples

```elm

-- Encodes a non-negative integer as a base32 string according to Crockford's encoding scheme.

Crockford.encode 1337 --> Ok "19S" : Result Crockford.Error String

-- Decodes a base32 string into a non-negative integer.

Crockford.decode "19S" --> Ok 1337 : Result Crockford.Error Int

-- Negative integers cannot be encoded.

Crockford.encode -1 --> Err NegativeNumberError : Result Crockford.Error String

```

It's also possible to have a checksum number appended to the string when encoded. This checksum number will be used to validate the correctness of the encoded number when decoding.

```elm

Crockford.encodeWithChecksum 32 --> Ok "10*" : Result Crockford.Error String

Crockford.decodeWithChecksum "10*" --> Ok 32 : Result Crockford.Error Int

Crockford.decodeWithChecksum "10~" --> Err Crockford.InvalidChecksum : Result Crockford.Error Int

```