Trait Rollout 

pub trait Rollout {
    type State: State;
    type ResponseGenerator: ResponseGenerator<State = Self::State>;

    // Required method
    fn play(
        &self,
        state: &Self::State,
        response_generator: &Self::ResponseGenerator,
    ) -> f32;
}

Rollout trait for MCTS search

The Rollout trait defines the interface for performing rollouts in a game state. It is used by the MCTS algorithm to simulate game play and evaluate the potential outcomes of different moves. It is implemented for specific game states in the game-specific code.

Type Parameters

• S - Game state type

Examples

#[derive(Debug, Clone, Default)]
struct TestAction;
struct TestResponseGen;
impl ResponseGenerator for TestResponseGen {
    type State = TestGameState;
    fn generate(&self, _state: &TestGameState) -> Vec<TestAction> { vec![TestAction] }
}
struct TestRollout;
impl Rollout for TestRollout {
    type State = TestGameState;
    type ResponseGenerator = TestResponseGen;
    fn play(&self, state: &TestGameState, _rg: &TestResponseGen) -> f32 { state.value as f32 }
}
let state = TestGameState { value: 42 };
let rollout = TestRollout;
let rg = TestResponseGen;
let score = rollout.play(&state, &rg);
assert_eq!(score, 42.0);

Required Associated Types

type State: State

The type representing the game state

type ResponseGenerator: ResponseGenerator<State = Self::State>

Required Methods

fn play( &self, state: &Self::State, response_generator: &Self::ResponseGenerator, ) -> f32

Performs a rollout (simulation) from the given state using the provided response generator, and returns the evaluated value.

The rollout is a simulation of the game from the given state to a terminal state, following simple heuristics or random moves. The result is a score in the range [-1.0, 1.0], where 1.0 indicates a win for the computer player, -1.0 indicates a loss, and 0.0 indicates a draw.

Arguments

• state - The game state to perform the rollout from
• response_generator - The response generator for producing legal actions

Returns

[-1.0, 1.0] score representing the outcome of the rollout from the perspective of the computer player.

Implementors