giga-chess 0.8.3

A rust chess library built for performance, handling game logic and legal/best move generation.
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137

use crate::game::piece::Piece;
use crate::game::square::Square;
use std::fmt::{Display, Formatter};

// https://www.chessprogramming.org/Encoding_Moves
#[derive(Debug, Default, Copy, Clone, PartialEq, Eq, Hash)]
#[cfg_attr(feature = "bincode", derive(bincode::Encode, bincode::Decode))]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
#[repr(transparent)]
pub struct ChessMove(u16);

impl ChessMove {
    pub fn new(from: u8, to: u8, move_type: ChessMoveType) -> Self {
        Self(((from as u16) << 10) | (((to & 0b111111) as u16) << 4) | (move_type as u16))
    }

    pub fn all_promotions(from: u8, to: u8) -> Vec<Self> {
        vec![
            Self::new(from, to, ChessMoveType::KnightPromotion),
            Self::new(from, to, ChessMoveType::BishopPromotion),
            Self::new(from, to, ChessMoveType::RookPromotion),
            Self::new(from, to, ChessMoveType::QueenPromotion),
        ]
    }

    pub fn all_promotions_capture(from: u8, to: u8) -> Vec<Self> {
        vec![
            Self::new(from, to, ChessMoveType::KnightPromotionCapture),
            Self::new(from, to, ChessMoveType::BishopPromotionCapture),
            Self::new(from, to, ChessMoveType::RookPromotionCapture),
            Self::new(from, to, ChessMoveType::QueenPromotionCapture),
        ]
    }

    pub fn get_from(&self) -> u8 {
        (self.0 >> 10) as u8
    }

    pub fn get_to(&self) -> u8 {
        ((self.0 & 0b00000011_11110000) >> 4) as u8
    }

    pub fn get_type(&self) -> ChessMoveType {
        ChessMoveType::from(self.0 as u8)
    }
}

#[derive(Debug, Copy, Clone, PartialEq, Eq)]
#[repr(u8)]
pub enum ChessMoveType {
    Quiet = 0,
    DoublePawnPush = 1,
    KingCastle = 2,
    QueenCastle = 3,
    Capture = 4,
    EnPassant = 5,
    Reserved6 = 6,
    Reserved7 = 7,
    KnightPromotion = 8,
    BishopPromotion = 9,
    RookPromotion = 10,
    QueenPromotion = 11,
    KnightPromotionCapture = 12,
    BishopPromotionCapture = 13,
    RookPromotionCapture = 14,
    QueenPromotionCapture = 15,
}

impl ChessMoveType {
    pub fn is_capture(&self) -> bool {
        (((*self as u8) >> 2) & 1) == 1
    }

    pub fn is_promotion(&self) -> bool {
        (*self as u8) >= 8
    }

    pub fn promotion_piece(&self) -> Option<Piece> {
        match self {
            Self::KnightPromotion | Self::KnightPromotionCapture => Some(Piece::Knight),
            Self::BishopPromotion | Self::BishopPromotionCapture => Some(Piece::Bishop),
            Self::RookPromotion | Self::RookPromotionCapture => Some(Piece::Rook),
            Self::QueenPromotion | Self::QueenPromotionCapture => Some(Piece::Queen),
            _ => None,
        }
    }
}

impl From<u8> for ChessMoveType {
    fn from(value: u8) -> Self {
        match value & 0b1111 {
            0 => ChessMoveType::Quiet,
            1 => ChessMoveType::DoublePawnPush,
            2 => ChessMoveType::KingCastle,
            3 => ChessMoveType::QueenCastle,
            4 => ChessMoveType::Capture,
            5 => ChessMoveType::EnPassant,
            6 => ChessMoveType::Reserved6,
            7 => ChessMoveType::Reserved7,
            8 => ChessMoveType::KnightPromotion,
            9 => ChessMoveType::BishopPromotion,
            10 => ChessMoveType::RookPromotion,
            11 => ChessMoveType::QueenPromotion,
            12 => ChessMoveType::KnightPromotionCapture,
            13 => ChessMoveType::BishopPromotionCapture,
            14 => ChessMoveType::RookPromotionCapture,
            15 => ChessMoveType::QueenPromotionCapture,
            _ => unreachable!(),
        }
    }
}

impl Display for ChessMove {
    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
        let from = Square::new(self.get_from()).to_string().to_lowercase();
        let to = Square::new(self.get_to()).to_string().to_lowercase();

        match self.get_type() {
            ChessMoveType::Quiet => write!(f, "{}-{}", from, to),
            ChessMoveType::DoublePawnPush => write!(f, "{} DPP", from),
            ChessMoveType::KingCastle => write!(f, "KC"),
            ChessMoveType::QueenCastle => write!(f, "QC"),
            ChessMoveType::Capture => write!(f, "{}-{} C", from, to),
            ChessMoveType::EnPassant => write!(f, "{}-{} EP", from, to),
            ChessMoveType::Reserved6 => write!(f, "R6"),
            ChessMoveType::Reserved7 => write!(f, "R7"),
            ChessMoveType::KnightPromotion => write!(f, "{}-{} PN", from, to),
            ChessMoveType::BishopPromotion => write!(f, "{}-{} PB", from, to),
            ChessMoveType::RookPromotion => write!(f, "{}-{} PR", from, to),
            ChessMoveType::QueenPromotion => write!(f, "{}-{} PQ", from, to),
            ChessMoveType::KnightPromotionCapture => write!(f, "{}-{} PN C", from, to),
            ChessMoveType::BishopPromotionCapture => write!(f, "{}-{} PB C", from, to),
            ChessMoveType::RookPromotionCapture => write!(f, "{}-{} PR C", from, to),
            ChessMoveType::QueenPromotionCapture => write!(f, "{}-{} PQ C", from, to),
        }
    }
}