types.gno

 1package chess
 2
 3// Board represents an 8x8 chess board matrix
 4type Board [8][8]string
 5
 6// CastlingRights tracks whether king or rooks have moved
 7type CastlingRights struct {
 8	WhiteKingMoved      bool
 9	WhiteLeftRookMoved  bool
10	WhiteRightRookMoved bool
11	BlackKingMoved      bool
12	BlackLeftRookMoved  bool
13	BlackRightRookMoved bool
14}
15
16// NewInitialBoard returns the standard starting position for a chess game
17func NewInitialBoard() Board {
18	var b Board
19
20	// Row 0 & 1: Black pieces (lowercase)
21	b[0] = [8]string{"r", "n", "b", "q", "k", "b", "n", "r"}
22	b[1] = [8]string{"p", "p", "p", "p", "p", "p", "p", "p"}
23
24	// Row 2 to 5: Empty squares
25	for i := 2; i < 6; i++ {
26		b[i] = [8]string{".", ".", ".", ".", ".", ".", ".", "."}
27	}
28
29	// Row 6 & 7: White pieces (uppercase)
30	b[6] = [8]string{"P", "P", "P", "P", "P", "P", "P", "P"}
31	b[7] = [8]string{"R", "N", "B", "Q", "K", "B", "N", "R"}
32
33	return b
34}
35
36// GetPieceEmoji converts a piece character string to a unicode chess emoji
37func GetPieceEmoji(p string) string {
38	switch p {
39	// White pieces
40	case "R": return "♖"
41	case "N": return "♘"
42	case "B": return "♗"
43	case "Q": return "♕"
44	case "K": return "♔"
45	case "P": return "♙"
46	// Black pieces
47	case "r": return "♜"
48	case "n": return "♞"
49	case "b": return "♝"
50	case "q": return "♛"
51	case "k": return "♚"
52	case "p": return "♟"
53	default: return " " // Empty square
54	}
55}
56
57// IsWhitePiece returns true if the piece belongs to White
58func IsWhitePiece(p string) bool {
59	return p >= "A" && p <= "Z"
60}
61
62// IsBlackPiece returns true if the piece belongs to Black
63func IsBlackPiece(p string) bool {
64	return p >= "a" && p <= "z"
65}
66
67// Abs returns the absolute value of an integer
68func Abs(x int) int {
69	if x < 0 {
70		return -x
71	}
72	return x
73}