# spirit_x4

**Repository Path**: mirrors_boostorg/spirit_x4

## Basic Information

- **Project Name**: spirit_x4
- **Description**: Boost.Spirit X4
- **Primary Language**: Unknown
- **License**: BSL-1.0
- **Default Branch**: develop
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 0
- **Forks**: 0
- **Created**: 2025-09-14
- **Last Updated**: 2026-03-21

## Categories & Tags

**Categories**: Uncategorized

**Tags**: None

## README

# Spirit.X4 [![Build Status](https://github.com/boostorg/spirit_x4/actions/workflows/ci.yml/badge.svg)](https://github.com/boostorg/spirit_x4/actions/workflows/ci.yml)

> **Spirit.X4 is currently under heavy development.**
>
> **This library is official, but still under progress, and is not part of the `boostorg/boost` superproject (yet).**
>
> For background information, see:
>
> - <https://lists.boost.org/archives/list/boost@lists.boost.org/thread/K3EQLEQJHEUBROB6ODUKTZHFP2FDUS2E/?sort=date>
> - <https://github.com/boostorg/spirit/issues/795>
> - <https://github.com/boostorg/spirit/pull/807>


[**Boost.Spirit.X4**](https://github.com/boostorg/spirit_x4) is a modern, header-only PEG parser combinator library for C++23. It lets you write EBNF-like grammars directly in C++ with deterministic, top-down parsing (ordered choice, lookahead, greedy repetition).

X4 succeeds [Boost.Spirit.X3](https://github.com/boostorg/spirit) and is redesigned for clarity, maintainability, and performance using modern C++ features such as concepts and constexpr.

X4 scales from quick prototypes to production parsers for DSLs, data formats, and interpreters.

### Supported Environments

- C++23 and C++26
- GCC 14
- Clang 21
- MSVC 2022

## How to use Spirit

### Step 1. Setup the Boost superproject

#### For applications:

```console
cd my_app

git submodule add https://github.com/boostorg/boost.git modules/boost
cd modules/boost

# Not required after X4 is officially shipped
git submodule add https://github.com/boostorg/spirit_x4.git libs/spirit_x4
```

#### For Spirit development:

```console
git clone https://github.com/boostorg/boost.git
cd boost

# Not required after X4 is officially shipped
git clone https://github.com/boostorg/spirit_x4.git libs/spirit_x4
```

### Step 2. Setup the dependent Boost libraries

We're trying hard to reduce these dependencies. We aim to remove these entirely in the future.

```console
git submodule update --init --depth 1 --recursive -- \
    tools/build tools/boost_install libs/assert libs/bind libs/config \
    libs/container_hash libs/core libs/describe libs/detail \
    libs/function libs/function_types libs/functional libs/fusion \
    libs/integer libs/io libs/mp11 libs/mpl libs/predef libs/preprocessor \
    libs/static_assert libs/throw_exception libs/tuple libs/type_index \
    libs/type_traits libs/typeof libs/utility libs/variant

# Linux
./bootstrap.sh
./b2 headers

# Windows
.\bootstrap.bat
.\b2 headers
```

### Step 3. Start using Spirit

#### For applications:

Edit your `CMakeLists.txt`:

```cmake
add_subdirectory(modules/boost/libs/spirit_x4)
target_link_libraries(my_app PRIVATE Boost::spirit_x4)
```

#### For developing Spirit:

```console
cd libs/spirit_x4
cmake -B build
```


## History

Date       | Boost | Commit  | Event
---------- | ----- | ------- | -----------------------------------------------
2025-09-18 | N/A   | `60c08ab` | Full CMake support added to X4.
2025-09-13 | N/A   | `9c0fc51` | Spirit.X3 and V2 are officially deprecated in favor of X4. Obsolete versions are feature-frozen and will accept security patches only.
2025-09-12 | N/A   | N/A     | The modernization effort was [officially approved](https://lists.boost.org/archives/list/boost@lists.boost.org/thread/K3EQLEQJHEUBROB6ODUKTZHFP2FDUS2E/?sort=date) as the independent library, [Spirit.X4]. Note: it is not part of the `boostorg/boost` superproject at this moment yet.
2025-09-05 | N/A   | `d21af8b` | The development of the C++23 modernization began.
2014-03-18 | 1.56  | `8a35332` | Spirit.X3 is added.
2013-12-14 | 1.56  | `c0537c8` | Phoenix V2 is retired.
2011-03-28 | 1.47  | `400a764` | [Phoenix V3] support is added to Spirit V2.
2009-04-30 | 1.41  | `5963a39` | [Spirit.Repository] appeared.
2008-04-13 | 1.36  | `ffd0cc1` | Spirit V2 (Qi, Karma, Lex, Phoenix V2) is added.
2006-08-23 | 1.35  | `2dc892b` | Fusion V1 is retired.
2003&#x2011;01&#x2011;31 | 1.30  | `8190791` | Spirit joined the Boost C++ Libraries.

[Spirit.X4]: https://github.com/boostorg/spirit_x4
[Phoenix V3]: http://boost.org/libs/phoenix
[Spirit.Repository]: http://www.boost.org/doc/libs/develop/libs/spirit/doc/html/spirit/repository.html