hyprfen-cpp

hyprfen-cpp is a reusable C++ implementation of the hyprfen chess FEN codec.

It encodes standard chess FENs into a compact binary representation and decodes them back into canonical standard FEN strings. The bitstream matches the Python reference implementation in hyprfen.

Status

• Library API: implemented
• CMake package/export metadata: implemented
• Golden compatibility tests against the Python reference bitstream: implemented

Build

cmake -S . -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build
ctest --test-dir build --output-on-failure

Public API

#include <hyprfen/hyprfen.hpp>

std::vector<std::uint8_t> blob = hyprfen::encode_fen(
    "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"
);
std::string fen = hyprfen::decode_fen(blob);
hyprfen::EncodeStats stats = hyprfen::encoding_stats(fen);

Consumption

Installed-package flow:

find_package(hyprfen CONFIG REQUIRED)
target_link_libraries(your_target PRIVATE hyprfen::hyprfen)

FetchContent flow:

include(FetchContent)

FetchContent_Declare(
  hyprfen
  GIT_REPOSITORY git@github.com:hyprchs/hyprfen-cpp.git
  GIT_TAG main
)
FetchContent_MakeAvailable(hyprfen)

target_link_libraries(your_target PRIVATE hyprfen::hyprfen)

Notes

• This codec supports standard chess FENs with standard KQkq castling notation.
• The decoder emits canonical standard FEN strings.
• The library is intentionally dependency-free beyond the C++ standard library.

For Python-first workflows, use the reference implementation in hyprfen.