lua-basex

Base encoding/decoding of any given alphabet using bitcoin style leading zero compression. This is a Lua implementation of base-x.

Installation

    $ luarocks install lua-basex

or

    $ opm get un-def/lua-basex

Dependencies

lua-basex has no dependencies (except, of course, Lua).

Compatibility

Tested with Lua 5.1, 5.2, and 5.3.

Examples

    local basex = require('basex')
    
    local encoded, decoded
    local base58alphabet = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'
    
    local base58 = basex(base58alphabet)
    decoded = base58:decode('5Kd3NBUAdUnhyzenEwVLy9pBKxSwXvE9FMPyR4UKZvpe6E3AgLr')
    print(decoded)
    --> [string of bytes]
    encoded = base58:encode(decoded)
    print(encoded)
    --> 5Kd3NBUAdUnhyzenEwVLy9pBKxSwXvE9FMPyR4UKZvpe6E3AgLr
    
    local base2 = basex('01')
    encoded = base2:encode('\0\255')
    print(encoded)
    --> 011111111
    decoded = base2:decode(encoded)
    print(decoded:byte(1, 2))
    --> 0      255

There are a bunch of predefined encoders/decoders:

• base16lower

• base16upper

• base58bitcoin

• base58flickr

• base58ripple

So, the first example can be rewritten as follows:

    local basex = require('basex')
    
    local decoded = basex.base58bitcoin:decode('5Kd3NBUAdUnhyzenEwVLy9pBKxSwXvE9FMPyR4UKZvpe6E3AgLr')
    local encoded = basex.base58bitcoin:encode(decoded)

An alphabet for any basex.baseXvariant predefined encoder/decoder is available as basex.alphabets.BASEXVARIANT (e.g., basex.alphabets.BASE58BITCOIN).