StateQueue

Let f(x) be an expensive operation which changes something to (or towards) state x. At most one f call may be in progress at any time. This type orchestrates a series of operations that eventually bring the state to some goal, while allowing the goal to change at any time.

struct StateQueue (

State

) {

this();

Promise!State delegate(State) stateFunc;

State oldState;

State newState;

State goalState;

Promise!void goalPromise;

Promise!void currentTransition;

this(Promise!State delegate(State) stateFunc, State initialState);

Promise!void setGoal(State state);

void setCurrentState(State state);

}

Constructors

this this(): Undocumented in source.
this this(Promise!State delegate(State) stateFunc, State initialState): Constructor.

Members

Functions

setCurrentState void setCurrentState(State state): Can be used to indicate that the state has been changed externally (e.g. to some "invalid"/"dirty" state). If a transition operation is already in progress, assume that it will change the state to the given state instead of its actual goal.
setGoal Promise!void setGoal(State state): Set the goal state. Starts off a transition operation if needed. Returns a promise that will be fulfilled when we reach the goal state, or rejected if the goal state changes before it is reached.

Variables

currentTransition Promise!void currentTransition;: The current state transition.
goalPromise Promise!void goalPromise;: The promise that will be fulfilled when we reach the goal state.
goalState State goalState;: The final state that we want to be in.
newState State newState;: The state that any current change is moving towards.
oldState State oldState;: The state that any current change is moving away from.
stateFunc Promise!State delegate(State) stateFunc;: The asynchronous implementation function which actually changes the state.

StateQueue

Constructors

Members

Functions

Variables

Meta

Source