pub fn search<S: State>(
tt: &Rc<RefCell<TranspositionTable>>,
sef: &impl StaticEvaluator<S>,
rg: &impl ResponseGenerator<State = S>,
s0: &Rc<S>,
max_depth: i32,
) -> Option<Rc<S>>Expand description
A minimax search implementation using alpha-beta pruning and a transposition table.
This function performs a complete minimax search to find the best move for the current player. It uses alpha-beta pruning for efficiency and a transposition table to avoid redundant calculations.
§Arguments
tt- A transposition table for caching previously computed positions. Can be reused across multiple searches.sef- The static evaluation functionrg- The response generators0- The state to search frommax_depth- Maximum search depth in plies
§Returns
Some(Rc<S>) containing the best move found, or None if no valid moves exist
§Examples
ⓘ
use std::cell::RefCell;
use std::rc::Rc;
use crate::minimax::search;
use crate::transposition_table::TranspositionTable;
// Set up the search components
let transposition_table = Rc::new(RefCell::new(TranspositionTable::new(1000, 100)));
let evaluator = MyStaticEvaluator::new();
let move_generator = MyResponseGenerator::new();
let game_state = Rc::new(MyGameState::initial_position());
// Search to depth 6
match search(&transposition_table, &evaluator, &move_generator, &game_state, 6) {
Some(best_move) => println!("Best move: {:?}", best_move),
None => println!("No moves available"),
}§Algorithm Details
The search uses:
- Minimax: Alternating maximizing and minimizing players
- Alpha-beta pruning: Early termination of unpromising branches
- Transposition table: Caching of previously evaluated positions
- Move ordering: Better moves searched first for more effective pruning