Crate lzd

Expand description

§lzd-rs

This library provides a Rust implementation of LZ double-factor factorization, an efficient grammar-based compression algorithm, proposed in the paper:

K Goto, H Bannai, S Inenaga, and M Takeda. LZD Factorization: Simple and Practical Online Grammar Compression with Variable-to-Fixed Encoding. In CPM, 2015.

§Examples

§Factorization

use lzd::compressor::Compressor;

fn main() {
    // Input text
    let text = "abaaabababaabbabab".as_bytes();

    // Factorization
    let mut factors = Vec::new();
    let defined_factors = Compressor::run(text, |id: usize| {
        factors.push(id);
    });

    // Output factors
    println!("factors: {:?}", factors);

    // Statistics
    println!("defined_factors: {:?}", defined_factors);
}

The output will be

factors: [97, 98, 97, 97, 256, 256, 256, 257, 98, 98, 258]
defined_factors: 261

NOTE: In this implementation, all 256 single characters are predefined as factors, so the number of factors defined will become 261.

§Defactorization

use lzd::decompressor::Decompressor;

fn main() {
    // Input text
    let factors = [97, 98, 97, 97, 256, 256, 256, 257, 98, 98, 258];

    // Defactorization
    let mut text = String::new();
    Decompressor::run(&factors, |c: u8| {
        text.push(c as char);
    });

    // Decoded text
    println!("text: {:?}", text);
}