CEL runtime

Note: This project is a temporary solution for using the CEL language from cel-rs in C++. This library will be deprecated when using the Rust implementations from C++ becomes viable.

Build a checked program once, then evaluate it repeatedly on your own reusable stack. This C++20 library supplies program builders, owning results, complete value types, and callable values. To compile CEL text instead of constructing operations in C++, start with CEL parser.

Build from source with CPM

Use CPM to build a static runtime with your application. After adding CPM to your project, declare the dependency and link your application target:

set(CPM_USE_LOCAL_PACKAGES OFF)
include(cmake/CPM.cmake)
CPMAddPackage("gh:stlab/[email protected]")
add_executable(client main.cpp)
target_link_libraries(client PRIVATE cel::runtime)

Include <cel/runtime.hpp> in your application. The build tutorial includes prerequisites, a complete application, and configure/build commands. No install step is needed.

Build your first program

Push two owned values, add a checked operation, and prepare the result:

cel::dyn_segment builder;
builder.just(cel::value::from(2.0));
builder.just(cel::value::from(3.0));
builder.op2<double, double, double>(
    [](double left, double right) { return left + right; });
auto program = std::move(builder).finish().prepare<double>();
cel::raw_stack stack;
double result = program.call(stack); // 5.0

The template arguments list the result first, followed by the operands in source order. Preparing checks the C++ boundary types once. You can call the prepared program again using the same stack.

Follow the tutorials

Read these guides in order:

1. Build and link the runtime with CPM.
2. Compile and reuse a program.
3. Add types and operations.
4. Choose execution and ownership boundaries.

The generated documentation places grouped APIs under Reference and symbol lookup under Index. Build it with cmake --preset docs followed by cmake --build --preset docs, then open build/docs/html/index.html.