Update README.md

pull/1/head
Clyne 4 years ago committed by GitHub
parent 50d13782ee
commit d2249cbbfa
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23

@ -1,2 +1,37 @@
# consteval-huffman # consteval-huffman
Compile-time Huffman coding compression using C++20
Allows for long string or data constants to be compressed at compile-time, with a small decoder routine for decompression at run-time.
Compression is achieved using Huffman coding, which works by creating codes for frequently-occuring characters.
## Use cases
**1. Text configurations (e.g. JSON)**
A ~3.5kB string of JSON can be compressed down ~2.5kB ([see it on Godbolt](https://godbolt.org/z/P6a9Kr)).
**2. Scripts (e.g. Lisp)**
A ~40 line commented sample of Lisp can be reduced from 1,662 bytes to 1,244 (418 bytes saved) ([on Godbolt](https://godbolt.org/z/c64Pzz)).
Compression will work best on not-small blocks of text or data. This is because a decoding tree must be stored with the compressed data, requiring three bytes per value.
## How to Use
```cpp
#include "consteval_huffman.hpp"
constexpr static const char some_data_raw[] = /* insert text here */;
constinit static const auto some_data = consteval_huffman<some_data_raw>();
// Or, with a set data length:
// ... some_data = consteval_huffman<some_data_raw, 1500>();
int main()
{
// Decompress and print out the data
for (auto decode = some_data.get_decoder(); decode; ++decode)
putchar(*decode);
}
```

Loading…
Cancel
Save