pubnub/core/event_engine/
state.rs

1use crate::{
2    core::event_engine::{EffectInvocation, Event, Transition},
3    lib::alloc::vec::Vec,
4};
5
6/// State machine state trait.
7///
8/// For transition, the state machine needs to know which effects should be
9/// dispatched during transition to target state in response to a specific
10/// event.
11///
12/// Types which are expected to be used as states should implement the trait.
13pub(crate) trait State: Clone + PartialEq {
14    type State: State;
15    type Invocation: EffectInvocation;
16    type Event: Event;
17
18    /// State enter effects invocations.
19    ///
20    /// The list of effect invocations that should be called when the event
21    /// engine enters state.
22    fn enter(&self) -> Option<Vec<Self::Invocation>>;
23
24    /// State exit effects invocations.
25    ///
26    /// The list of effect invocations that should be called when the event
27    /// engine leaves state.
28    fn exit(&self) -> Option<Vec<Self::Invocation>>;
29
30    /// System event handler.
31    ///
32    /// State has information about the next state into which the state machine
33    /// should switch and a list of effects invocations which should be
34    /// scheduled.
35    fn transition(
36        &self,
37        event: &<<Self as State>::Invocation as EffectInvocation>::Event,
38    ) -> Option<Transition<Self::State, Self::Invocation>>;
39
40    /// [`Transition`] build helper.
41    ///
42    /// Transition to a new state is a composite operation which includes
43    /// dispatching of [`exit`] effect invocations of receiver, followed by
44    /// dispatch of provided transition effect `invocations` and [`enter`]
45    /// effect invocations of target state.
46    fn transition_to(
47        &self,
48        state: Option<Self::State>,
49        invocations: Option<Vec<Self::Invocation>>,
50    ) -> Transition<Self::State, Self::Invocation>;
51}
pubnub/core/event_engine/state.rs

pubnub/core/event_engine/
state.rs
