An Elixir implementation of pieroxy/lz-string, an LZ-based compression algorithm.

iex> LZString.compress("hello, i am a 猫")
<<5, 133, 48, 54, 96, 246, 3, 64, 4, 9, 107, 2, 24, 22, 217, 180, 53, 51, 144, 0>>
iex> LZString.decompress(<<5, 133, 48, 54, 96, 246, 3, 64, 4, 9, 107, 2, 24, 22, 217, 180, 53, 51, 144, 0>>)
"hello, i am a 猫"
iex> LZString.compress_base64("hello, i am a 猫")
"BYUwNmD2A0AECWsCGBbZtDUzkAA="
iex> LZString.decompress_base64("BYUwNmD2A0AECWsCGBbZtDUzkA==")
"hello, i am a 猫"

Add lz_string to your list of dependencies in mix.exs:

def deps do
  [{:lz_string, "~> 0.0.8"}]
end

The tests compare LZString's output against that produced by the JS reference implementation (by way of a janky node.js Port). You'll need to install the node module in the root directory of the project beforehand:

$ npm install lz-string

Depending on how the port output is flushed, you'll once in a while get an error that complains about something like :erlang.binary_to_integer("64'\n>"), those are safe to ignore, and you can re-run the tests to try again. I'll gladly accept a PR to switch to https://github.com/awetzel/node_erlastic <3.

The Base64 that the reference library produces is invalid, but we can still use it as the end-of-message indication is a dictionary marker rather than the actual end-of-input, so it may be academic. This library will properly decompress the invalid base64, and produce valid base64 output during compression.