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use mv::Move;
use piece::Piece;
use position::*;
use square::*;
pub struct Board {
position: Position,
stack: Vec<StackElem>,
}
#[derive(Clone)]
struct StackElem {
pub key: u64,
pub captured: Option<(Piece, Square)>,
pub state: State,
pub mv: Move,
}
impl Board {
pub fn new(fen: &str) -> Board {
let position = Position::from_fen(fen).unwrap();
Board {
position: position,
stack: Vec::new(),
}
}
pub fn position(&self) -> &Position {
&self.position
}
pub fn key(&self) -> u64 {
self.position.hash_key()
}
pub fn depth(&self) -> usize {
self.stack.len()
}
pub fn make(&mut self, mv: Move) {
let before_state = self.position.state().clone();
let key = self.position.hash_key();
let capture = self.position.make(mv);
self.stack.push(StackElem {
key: key,
captured: capture,
state: before_state,
mv: mv,
})
}
pub fn unmake(&mut self) {
let elem = self.stack.pop().unwrap();
self.position
.unmake(elem.mv, elem.captured, &elem.state, elem.key);
}
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn test_key() {
let mut tree = Board::new(STARTING_POSITION_FEN);
let key_init = tree.key();
let mv_a = Move::new_push(D2, D4);
let mv_b = Move::new_push(G7, G5);
let mv_c = Move::new_push(B1, A3);
let mv_d = Move::new_push(G5, G4);
tree.make(mv_a);
tree.make(mv_b);
tree.make(mv_c);
tree.make(mv_d);
let key_after_moves = tree.key();
tree.unmake();
tree.unmake();
tree.unmake();
tree.unmake();
assert_eq!(tree.key(), key_init);
tree.make(mv_c);
tree.make(mv_b);
tree.make(mv_a);
tree.make(mv_d);
assert_eq!(tree.key(), key_after_moves);
}
}