The package LZ78 can be used to compress and decompress strings into something nice: emojis.
LZ78 is a lossless data compression algorithm, which form the basis of several ubiquitous compression schemes, including GIF and the DEFLATE algorithm used in PNG and ZIP. It has a simple algorithm which consist of finding repeating phrases (sequences of characters) and storing them in a tree like dictionary.
We have built a full working demo at emoji-compress.com ‼
- Compress function will iterate a string (slice of byte) character by character and create a dictionary embedded in the output.
- Decompress function will use the embedded dictionary to recompose original string.
- the emojis database has only around 1000 unique emojis, so the maximum length of a source text is limited
- the output length of the text could be bigger than the origina, if no sequences of characters repeat
// Compress
in := "Play with emojis!"
out, err := CompressString(in)
if err != nil {
log.Panic(err)
}
fmt.Printf("%s", out)
// Output: 😀P😀l😀a😀y😀 😀w😀i😀t😀h😃e😀m😀o😀j😅s😀!
// Decompress
in := "😀P😀l😀a😀y😀 😀w😀i😀t😀h😃e😀m😀o😀j😅s😀!"
out, err := DecompressString(in)
if err != nil {
log.Panic(err)
}
fmt.Printf("%s", out)
// Output: Play with emojis!This package has unit tests, GoDoc and Examples.
- https://de.wikipedia.org/wiki/LZ78
- https://w3.ual.es/~vruiz/Docencia/Apuntes/Coding/Text/02-string_encoding/03-LZ78/index.html
- http://compressions.sourceforge.net/LempelZiv.html
- http://www.stringology.org/DataCompression/lz78/index_en.html
- https://unicode.org/emoji/charts/full-emoji-list.html
This package is part of a group of emoji-related encoding and compression algorithms built for fun and academic purposes in Go.
Copyright (c) 2017 B.G.Adrian & @Davidescus