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
138
139
140
141

#![allow(dead_code)]

use std::prelude::v1::*;

use color::*;

pub type Square = u8;

pub const A1: Square = 0;
pub const B1: Square = 1;
pub const C1: Square = 2;
pub const D1: Square = 3;
pub const E1: Square = 4;
pub const F1: Square = 5;
pub const G1: Square = 6;
pub const H1: Square = 7;
pub const A2: Square = 8;
pub const B2: Square = 9;
pub const C2: Square = 10;
pub const D2: Square = 11;
pub const E2: Square = 12;
pub const F2: Square = 13;
pub const G2: Square = 14;
pub const H2: Square = 15;
pub const A3: Square = 16;
pub const B3: Square = 17;
pub const C3: Square = 18;
pub const D3: Square = 19;
pub const E3: Square = 20;
pub const F3: Square = 21;
pub const G3: Square = 22;
pub const H3: Square = 23;
pub const A4: Square = 24;
pub const B4: Square = 25;
pub const C4: Square = 26;
pub const D4: Square = 27;
pub const E4: Square = 28;
pub const F4: Square = 29;
pub const G4: Square = 30;
pub const H4: Square = 31;
pub const A5: Square = 32;
pub const B5: Square = 33;
pub const C5: Square = 34;
pub const D5: Square = 35;
pub const E5: Square = 36;
pub const F5: Square = 37;
pub const G5: Square = 38;
pub const H5: Square = 39;
pub const A6: Square = 40;
pub const B6: Square = 41;
pub const C6: Square = 42;
pub const D6: Square = 43;
pub const E6: Square = 44;
pub const F6: Square = 45;
pub const G6: Square = 46;
pub const H6: Square = 47;
pub const A7: Square = 48;
pub const B7: Square = 49;
pub const C7: Square = 50;
pub const D7: Square = 51;
pub const E7: Square = 52;
pub const F7: Square = 53;
pub const G7: Square = 54;
pub const H7: Square = 55;
pub const A8: Square = 56;
pub const B8: Square = 57;
pub const C8: Square = 58;
pub const D8: Square = 59;
pub const E8: Square = 60;
pub const F8: Square = 61;
pub const G8: Square = 62;
pub const H8: Square = 63;
pub const OUT: Square = 64;

pub trait SquareExt {
    fn from_coord(s: &str) -> Self;
    fn to_coord(&self) -> String;
    fn file_to_char(&self) -> char;
    fn rank_to_char(&self) -> char;
    fn file(&self) -> u8;
    fn rank(&self) -> u8;
    fn flip(&self, c: Color) -> Self;
}

impl SquareExt for Square {
    fn from_coord(s: &str) -> Self { // TODO: -> Option<Self>
        let bytes = s.as_bytes();

        ((bytes[0] - b'a') + 8 * (bytes[1] - b'1')) as Square
    }

    fn to_coord(&self) -> String {
        // FIXME: OUT.to_coord() => a9
        format!("{}{}", self.file_to_char(), self.rank_to_char())
    }

    fn rank_to_char(&self) -> char {
        (b'1' + self.rank()) as char
    }

    fn file_to_char(&self) -> char {
        (b'a' + self.file()) as char
    }

    fn file(&self) -> u8 {
        *self as u8 % 8
    }

    fn rank(&self) -> u8 {
        *self as u8 / 8
    }

    fn flip(&self, c: Color) -> Self {
        *self ^ (A8 * c)
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_from_coord() {
        let sq: Square = SquareExt::from_coord("e2");
        assert_eq!(sq, E2);
    }

    #[test]
    fn test_to_coord() {
        assert_eq!(A1.to_coord(), "a1");
        assert_eq!(E2.to_coord(), "e2");
        assert_eq!(C6.to_coord(), "c6");
    }

    #[test]
    fn test_flip() {
        assert_eq!(E2.flip(WHITE), E2);
        assert_eq!(E2.flip(BLACK), E7);
    }
}