This library is a robust and efficient refactored version of the base-x library, now optimized with TypeScript. It provides fast base encoding and decoding of any given alphabet using bitcoin style leading zero compression.
Example with Base58:
import { base58 } from '@describble/base-x';
const decoded = base58.decode('5Kd3NBUAdUnhyzenEwVLy9pBKxSwXvE9FMPyR4UKZvpe6E3AgLr');
console.log(decoded);
// => Uint8Array(33) [
// 128, 237, 219, 220, 17, 104, 241, 218,
// 234, 219, 211, 228, 76, 30, 63, 143,
// 90, 40, 76, 32, 41, 247, 138, 210,
// 106, 249, 133, 131, 164, 153, 222, 91,
// 25
// ]
console.log(base58.encode(decoded));
// => 5Kd3NBUAdUnhyzenEwVLy9pBKxSwXvE9FMPyR4UKZvpe6E3AgLr
This library supports a variety of base encoding alphabets. Below is a list of commonly recognized alphabets, along with their respective base:
Base | Alphabet |
---|---|
2 | 01 |
8 | 01234567 |
11 | 0123456789a |
16 | 0123456789abcdef |
32 | 0123456789ABCDEFGHJKMNPQRSTVWXYZ |
32z | ybndrfg8ejkmcpqxot1uwisza345h769 |
36 | 0123456789abcdefghijklmnopqrstuvwxyz |
58 | 123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz |
62 | 0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ |
64 | ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/ |
67 | ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_.!~ |
This library encodes octet arrays by performing long divisions on all significant digits in the array, creating a representation of that number in the new base. For every leading zero in the input (not significant as a number), it is encoded as a single leader character, the first character in the alphabet which decodes as 8 bits. The other characters' values depend upon the base. For instance, a base58 alphabet packs roughly 5.858 bits per character.
Interestingly, the encoded string '000f' (using a base16, 0-f alphabet) will actually decode to 4 bytes unlike a canonical hex encoding which uniformly packs 4 bits into each character. Although this might seem unusual, it allows us to eliminate the need for padding, and it also works for bases like 43.
While using the decodeUnsafe
and decode
methods, please note that if the source string contains a character not recognized in the base encoding scheme, the decodeUnsafe
function will return undefined
, while decode
will throw an Error
. Always ensure the validity of your source string to prevent unexpected errors or results.
Contributions are always welcome! Feel free to report bugs or request features by submitting issues, and feel free to propose improvements or new features via pull requests.
This library is a derivative of the base58 implementation from bitcoin/bitcoin
, generalized for variable length alphabets. It is licensed under the MIT license.