StateForward C++

A C++ finite state machine (FSM) library that provides a flexible and type-safe way to define and execute state machines.

Features

• Hierarchical state machines
• Entry/exit/activity actions
• Guards and effects on transitions
• Choice pseudo-states
• Local and external transitions
• Event-based transitions
• Storage for user data

Requirements

• C++20 compiler
• CMake 3.15 or higher
• spdlog
• stduuid
• Google Test (for running tests)

Building

mkdir build
cd build
cmake ..
make

Running Tests

cd build
ctest

Usage Example

#include "stateforward.hpp"
#include <iostream>

using namespace stateforward;

int main() {
    // Create a simple state machine
    auto model = make_model({
        initial("foo"),
        state("foo"),
        state("bar"),
        transition({
            on({"foo"}),
            source("foo"),
            target("bar"),
            effect([](const Context& ctx, const Event& event) {
                std::cout << "Transitioning from foo to bar\n";
            })
        })
    });

    // Create FSM instance
    auto fsm = std::make_unique<FSM>(std::move(model));

    // Initial state should be "foo"
    std::cout << "Current state: " << fsm->state() << "\n";

    // Dispatch event to trigger transition
    fsm->dispatch(event_kind("foo"));

    // State should now be "bar"
    std::cout << "Current state: " << fsm->state() << "\n";

    return 0;
}

License

MIT License