Spirit.X4 is currently under heavy development. It is considered NOT USABLE in applications yet.

This library is official, developed under organization-wide consensus, but not part of the boostorg/boost superproject (yet).

We will not accept contributions from outside collaborators until the X3 -> X4 transition is complete.

For background information, see:

• https://lists.boost.org/archives/list/[email protected]/thread/K3EQLEQJHEUBROB6ODUKTZHFP2FDUS2E/?sort=date
• boostorg/spirit#795
• boostorg/spirit#807

... WIP content follows ...

Spirit.X4

Spirit is a set of C++ libraries for parsing and output generation implemented as Domain Specific Embedded Languages (DSEL) using Expression templates and Template Meta-Programming. The Spirit libraries enable a target grammar to be written exclusively in C++. Inline grammar specifications can mix freely with other C++ code and, thanks to the generative power of C++ templates, are immediately executable.

Spirit.X4 (4th generation)

Stay tuned!

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:

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:

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.

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/endian \
    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 --with-toolset=gcc
./b2 headers

# Windows
.\bootstrap.bat
.\b2 headers

Step 3. Start using Spirit

For applications:

Edit your CMakeLists.txt:

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

For developing Spirit:

cd libs/spirit_x4
cmake -B build

Brief History

Date	Boost	Commit	Event
2014-03-18	1.56	8a353328	Spirit.X3 is added
2013-12-14	1.56	c0537c82	Phoenix V2 is retired
2011-03-28	1.47	400a764d	Phoenix V3 support added to Spirit V2
2009-04-30	1.41	5963a395	Spirit.Repository is appeared
2008-04-13	1.36	ffd0cc10	Spirit V2 (Qi, Karma, Lex, Phoenix V2) is added
2006-08-23	1.35	2dc892b4	Fusion V1 is retired
2003-01-31	1.30	81907916	Spirit is the part of the Boost