fxsm

一个用于枚举的非常简单的状态机过程宏。

它是如何工作的

它简单地为您枚举的适当 StateMachine 特性的方法生成匹配条件。您可以通过 StateMachine 特性来使用状态机。

用法

1. 在您的 Cargo.toml 中添加 fxsm 依赖项

[dependencies]
fxsm-derive = "0.2"
fxsm = "0.2"

2. 创建状态机

#[macro_use]
extern crate fxsm_derive;
extern crate fxsm;


#[derive(Clone, Debug, FiniteStateMachine)]
enum CupState {
    #[state_transitions(Checkins, Aborted, Rescheduled)]
    Waiting,
    #[state_transitions(InProgress, Aborted, Rescheduled)]
    Checkins,
    #[state_transitions(Finished, Aborted, Rescheduled)]
    InProgress(String),

    // Finish-states
    Aborted(u64),
    Rescheduled { info: String },
    Finished,
}

3. 使用它

fn main() {
    use fxsm::{ StateMachine };
    let mut fsm = CupState::Waiting;
    assert_eq!(CupState::finish_states(), 3);
    // must not be able to change to itself
    assert!(!fsm.can_change(CupState::Waiting));
    assert!(fsm.can_change(CupState::Checkins));
    assert!(!fsm.can_change(CupState::InProgress(String::default())));
    assert!(fsm.can_change(CupState::Aborted(0u64)));
    assert!(fsm.can_change(CupState::Rescheduled{info: String::default()}));
    assert!(!fsm.can_change(CupState::Finished));
    assert!(!fsm.at_finish_state());

    assert!(fsm.change(CupState::Checkins));
    assert!(!fsm.can_change(CupState::Waiting));
    assert!(fsm.can_change(CupState::Aborted(0u64)));
    assert!(fsm.can_change(CupState::Rescheduled{info: String::default()}));
    assert!(fsm.can_change(CupState::InProgress(String::default())));
    assert!(!fsm.can_change(CupState::Finished));
    assert!(!fsm.at_finish_state());

    // You still always able to change it without FSM rules:
    fsm = CupState::Finished;
    assert!(fsm.at_finish_state());
    assert!(CupState::is_finish_state(CupState::Finished));
    assert!(CupState::is_finish_state(CupState::Aborted(0u64)));
    assert!(CupState::is_finish_state(CupState::Rescheduled{ info: String::default()}));
    assert!(!CupState::is_finish_state(CupState::Waiting));
    assert!(!CupState::is_finish_state(CupState::Checkins));
    assert!(!CupState::is_finish_state(CupState::InProgress(String::default())));
}

更多和更新的示例在 示例目录 中。

许可证

本项目采用 MIT 许可证。