consteval-huffman

Allows for long strings of text or data to be compressed at compile-time, with an efficient decoder routine for decompression at run-time. The decoder conforms to std::forward_iterator, allowing for use in ranged-for or standard algorithms.

Compression is achieved using Huffman coding, which works by creating short codes (measured in bits) for frequently-occuring characters. This works best on larger pieces of data, or more so data that is limited in its range of values (e.g. written text).

Use cases

1. Text configurations (e.g. JSON)

A ~3.5kB string of JSON can be compressed down ~2.5kB (see it on Godbolt).

2. Scripts (e.g. Lisp)

A ~40 line comment-including sample of Lisp can be reduced from 1,662 bytes to 1,244 (418 bytes saved) (Godbolt).

How to Use

#include "consteval_huffman.hpp"

// Using the _huffman suffix creates an object with the compressed data.
// If data is not smaller after compression, the object will keep the data uncompressed.
constinit auto some_data = "This is my string of data"_huffman;

int main()
{
    // Decompress and print out the data
    for (auto c : some_data)
        putchar(c);
}