Changed visibility from package to interal

Sources/Engine/Board.swift

@@ -29,19 +29,19 @@ public class Board: CustomStringConvertible {
 	public private(set) var fen: Fen
 
 	public func setBoard() throws {
-		var file: UInt8 = 1
-		var rank: UInt8 = 8
-		var index: UInt8 = 0
+		var file: Int8 = 1
+		var rank: Int8 = 8
+		var index: Int8 = 0
 		var b: [Square] = squares
 		for c in fen.placement {
-			let r = (8 - Int(rank)) % 8
+			let r = 8 - Int(rank)
 			if c == "/" {
 				if file != 9 {
 					throw Fen.FenError.NotAppropriateLength(n: file, column: index)
 				}
 				rank -= 1
 				file = 0
-			} else if c.isWholeNumber, let n = UInt8(String(c)) {
+			} else if c.isWholeNumber, let n = Int8(String(c)) {
 				if n < 1 {
 					throw Fen.FenError.NumberTooSmall(n: n, column: index)
 				} else if n > 8 {
@@ -82,20 +82,22 @@ public class Board: CustomStringConvertible {
 			file += 1
 			index += 1
 		}
+		#if DEBUG 
 			print(b)	
+		#endif	
 		squares = b
 	}
 
 	public required init(fen: Fen = 
 		.init(fen: "rnbqkbnr/pppppppp/8/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1")
 	) {
-		var rank: UInt8 = 8
+		var rank: Int8 = 8
 		self.fen = fen
 		for i in 0...63 {
-			let index = UInt8(i)
+			let index = Int8(i)
 			let square = Square(
 				position: .init(file: (index % 8) + 1, rank: rank),
-				index: index,
+				index: i,
 				color: index % 2 != rank % 2 ? .Black : .White)
 			squares.append(square)
 			if (index + 1) % 8 == 0 {

Sources/Engine/FEN.swift

@@ -64,10 +64,10 @@ public struct Fen: CustomStringConvertible {
 	}
 
 	public enum FenError: Error {
-		case InvalidCharacter(c: String, column: UInt8)
-		case NumberTooBig(n: UInt8, column: UInt8)
-		case NumberTooSmall(n: UInt8, column: UInt8)
-        case NotAppropriateLength(n: UInt8, column: UInt8)
+		case InvalidCharacter(c: String, column: Int8)
+		case NumberTooBig(n: Int8, column: Int8)
+		case NumberTooSmall(n: Int8, column: Int8)
+        case NotAppropriateLength(n: Int8, column: Int8)
 	}
 
 	public var description: String {

Sources/Engine/Pieces/Bishop.swift

@@ -1,31 +1,40 @@
-package class Bishop: Piece {
-	package weak var board: Board?
-	package var kind: Kind = .Bishop
+internal final class Bishop: Piece, DiagonalMoves {
+	internal weak var board: Board?
+	internal var kind: Kind = .Bishop
 
-	package var unicodeRepresentation: String {
+	internal var unicodeRepresentation: String {
 		return color == .Black ? "♝" : "♗"
 	}
-	package var color: Color
+	internal var color: Color
 
-	package var position: Square.Position
+	internal var position: Square.Position
 
-	package var pseudoLegalPositions: [Square.Position] {
-		return []
+	internal var pseudoLegalPositions: [Square.Position] {
+		return getDiagonalMoves(from: position)
 	}
 
-	package var legalPositions: [Square.Position] {
-		return pseudoLegalPositions.filter { isLegal(pos: $0) }
+	internal var legalPositions: [Square.Position] {
+		return pseudoLegalPositions.filter { isLegal(on: $0) }
 	}
 
-	package func move(dst: Square.Position) -> Bool {
+	internal func move(to dst: Square.Position) -> Bool {
 		return false
 	}
 
-	package func isLegal(pos: Square.Position) -> Bool {
+	internal func isLegal(on pos: Square.Position) -> Bool {
+		if let board = board, let s = board[pos] {
+			if let p = s.piece {
+				if p.color == color { return false }
+				if p.kind == .King {
+					// TODO: Notify board of check
 					return false
 				}
+			}
+		}
+		return true
+	}
 
-	package init(color: Color, on position: Square.Position) {
+	internal init(color: Color, on position: Square.Position) {
 		self.color = color
 		self.position = position
 	}

Sources/Engine/Pieces/CommonMoves.swift

@@ -0,0 +1,19 @@
+internal protocol DiagonalMoves {
+    func getDiagonalMoves(from pos: Square.Position) -> [Square.Position]
+}
+
+extension DiagonalMoves {
+    func getDiagonalMoves(from pos: Square.Position) -> [Square.Position] {
+        return []
+    }
+}
+
+internal protocol LinearMoves {
+    func getLinearMoves(from pos: Square.Position) -> [Square.Position]
+}
+
+extension LinearMoves {
+    func getLinearMoves(from pos: Square.Position) -> [Square.Position] {
+        return []
+    }
+}

Sources/Engine/Pieces/King.swift

@@ -1,31 +1,41 @@
-package class King: Piece {
-	package weak var board: Board?
-	package var kind: Kind = .King
+internal final class King: Piece {
+	internal weak var board: Board?
+	internal var kind: Kind = .King
 
-	package var unicodeRepresentation: String {
+	internal var unicodeRepresentation: String {
 		return color == .Black ? "♛" : "♕"
 	}
-	package var color: Color
+	internal var color: Color
 
-	package var position: Square.Position
+	internal var position: Square.Position
 
-	package var pseudoLegalPositions: [Square.Position] {
+	internal var pseudoLegalPositions: [Square.Position] {
 		return []
 	}
 
-	package var legalPositions: [Square.Position] {
-		return pseudoLegalPositions.filter { isLegal(pos: $0) }
+	internal var legalPositions: [Square.Position] {
+		return pseudoLegalPositions.filter { isLegal(on: $0) }
 	}
 
-	package func move(dst: Square.Position) -> Bool {
+	internal func move(to dst: Square.Position) -> Bool {
 		return false
 	}
 
-	package func isLegal(pos: Square.Position) -> Bool {
+	internal func isLegal(on pos: Square.Position) -> Bool {
+		if let board = board, let s = board[pos] {
+			if let p = s.piece {
+				if p.color == color { return false }
+				if p.kind == .King {
+					// TODO: Notify board of check
 					return false
 				}
+			}
 
-	package init(color: Color, on position: Square.Position) {
+		}
+		return true
+	}
+
+	internal init(color: Color, on position: Square.Position) {
 		self.color = color
 		self.position = position
 	}

Sources/Engine/Pieces/Knight.swift

@@ -1,31 +1,54 @@
-package class Knight: Piece {
-	package weak var board: Board?
-	package var kind: Kind = .Knight
+internal final class Knight: Piece {
+	internal weak var board: Board?
+	internal var kind: Kind = .Knight
 
-	package var unicodeRepresentation: String {
+	internal var unicodeRepresentation: String {
 		return color == .Black ? "♞" : "♘"
 	}
-	package var color: Color
+	internal var color: Color
 
-	package var position: Square.Position
+	internal var position: Square.Position
 
-	package var pseudoLegalPositions: [Square.Position] {
-		return []
+	internal var pseudoLegalPositions: [Square.Position] {
+		let directions: [Square.Position] = [
+			.init(file: position.file + 1, rank: position.rank + 2),
+			.init(file: position.file - 1, rank: position.rank + 2),
+			.init(file: position.file + 1, rank: position.rank - 2),
+			.init(file: position.file - 1, rank: position.rank - 2),
+			.init(file: position.file + 2, rank: position.rank + 1),
+			.init(file: position.file - 2, rank: position.rank + 1),
+			.init(file: position.file + 2, rank: position.rank - 1),
+			.init(file: position.file - 2, rank: position.rank - 1)
+		]
+		return directions.filter {
+			let index = $0.index
+			return index < 0 || index > 63
+		}
 	}
 
-	package var legalPositions: [Square.Position] {
-		return pseudoLegalPositions.filter { isLegal(pos: $0) }
+	internal var legalPositions: [Square.Position] {
+		return pseudoLegalPositions.filter { isLegal(on: $0) }
 	}
 
-	package func move(dst: Square.Position) -> Bool {
+	internal func move(to dst: Square.Position) -> Bool {
 		return false
 	}
 
-	package func isLegal(pos: Square.Position) -> Bool {
+	internal func isLegal(on pos: Square.Position) -> Bool {
+		if let board = board, let s = board[pos] {
+			if let p = s.piece {
+				if p.color == color { return false }
+				if p.kind == .King {
+					// TODO: Notify board of check
 					return false
 				}
+			}
 
-	package init(color: Color, on position: Square.Position) {
+		}
+		return true
+	}
+
+	internal init(color: Color, on position: Square.Position) {
 		self.color = color
 		self.position = position
 	}

Sources/Engine/Pieces/Pawn.swift

@@ -1,20 +1,32 @@
-package class Pawn: Piece {
-	package var kind: Kind = .Pawn
-	package weak var board: Board?
-	package var color: Color
-	package var position: Square.Position
-	package var pseudoLegalPositions: [Square.Position] {
-		return []
+internal final class Pawn: Piece {
+	internal var kind: Kind = .Pawn
+	internal weak var board: Board?
+	internal var color: Color
+	internal var position: Square.Position
+	internal var pseudoLegalPositions: [Square.Position] {
+		let sign: Int8 = color == .Black ? -1 : 1
+		let rank = Int8(position.rank)
+		let directions: [Square.Position] = [
+			.init(file: position.file, rank: rank + 1 * sign),
+			.init(file: position.file, rank: rank + 2 * sign),
+			.init(file: position.file + 1, rank: rank + 1 * sign),
+			.init(file: position.file - 1, rank: rank + 1 * sign)
+		]
+		// TODO: Handle en passant
+		return directions.filter { 
+			let index = $0.index
+			return index < 1 || index > 63
 		}
-	package var legalPositions: [Square.Position] {
-		return pseudoLegalPositions.filter { isLegal(pos: $0) }
+	}
+	internal var legalPositions: [Square.Position] {
+		pseudoLegalPositions.filter { isLegal(on: $0) }
 	}
 
-	package var unicodeRepresentation: String {
-		return color == .Black ? "♟" : "♙"
+	internal var unicodeRepresentation: String {
+		color == .Black ? "♟" : "♙"
 	}
 
-	package func move(dst: Square.Position) -> Bool {
+	internal func move(to dst: Square.Position) -> Bool {
 		guard board != nil else {
 			return false
 		}
@@ -33,18 +45,22 @@ package class Pawn: Piece {
 		return true
 	}
 
-	package func isLegal(pos: Square.Position) -> Bool {
+	internal func isLegal(on pos: Square.Position) -> Bool {
 		// TODO: Handle "En-Passant"
 		if let board = board, let s = board[pos] {
 			if let p = s.piece {
 				if p.color == color { return false }
+				if p.kind == .King {
+					// TODO: Notify board of check
+					return false
+				}
 			}
 
 		}
 		return true
 	}
 
-	package init(
+	internal init(
 		color: Color, on position: Square.Position
 	) {
 		self.color = color

Sources/Engine/Pieces/Piece.swift

@@ -1,7 +1,7 @@
-public enum Kind: String, CaseIterable {
+internal enum Kind: String, CaseIterable {
 	case Pawn, Knight, Bishop, Rook, Queen, King
 
-	public var value: Int8 {
+	internal var value: Int8 {
 		switch self {
 		case .Pawn: 1
 		case .Bishop: 3
@@ -12,7 +12,7 @@ public enum Kind: String, CaseIterable {
 		}
 	}
 
-	public static subscript(_ c: Character) -> (Self, Color)? {
+	internal static subscript(_ c: Character) -> (Self, Color)? {
 		let v = c.uppercased()
 
 		guard
@@ -39,7 +39,7 @@ public enum Kind: String, CaseIterable {
 	}
 }
 
-public protocol Piece {
+internal protocol Piece {
 	var board: Board? { get }
 	var color: Color { get }
 	var unicodeRepresentation: String { get }
@@ -47,6 +47,6 @@ public protocol Piece {
 	var position: Square.Position { get }
 	var pseudoLegalPositions: [Square.Position] { get }
 	var legalPositions: [Square.Position] { get }
-	func move(dst: Square.Position) -> Bool
-	func isLegal(pos: Square.Position) -> Bool
+	func move(to dst: Square.Position) -> Bool
+	func isLegal(on pos: Square.Position) -> Bool
 }

Sources/Engine/Pieces/Queen.swift

@@ -1,31 +1,42 @@
-package class Queen: Piece {
-	package weak var board: Board?
-	package var kind: Kind = .Queen
+internal final class Queen: Piece, LinearMoves, DiagonalMoves {
+	internal weak var board: Board?
+	internal var kind: Kind = .Queen
 
-	package var unicodeRepresentation: String {
+	internal var unicodeRepresentation: String {
 		return color == .Black ? "♛" : "♕"
 	}
-	package var color: Color
+	internal var color: Color
 
-	package var position: Square.Position
+	internal var position: Square.Position
 
-	package var pseudoLegalPositions: [Square.Position] {
-		return []
+	internal var pseudoLegalPositions: [Square.Position] {
+		return getDiagonalMoves(from: position) + getLinearMoves(from: position)
 	}
 
-	package var legalPositions: [Square.Position] {
-		return pseudoLegalPositions.filter { isLegal(pos: $0) }
+	internal var legalPositions: [Square.Position] {
+		return pseudoLegalPositions.filter { isLegal(on: $0) }
 	}
 
-	package func move(dst: Square.Position) -> Bool {
+	internal func move(to dst: Square.Position) -> Bool {
+		
 		return false
 	}
 
-	package func isLegal(pos: Square.Position) -> Bool {
+	internal func isLegal(on pos: Square.Position) -> Bool {
+		if let board = board, let s = board[pos] {
+			if let p = s.piece {
+				if p.color == color { return false }
+				if p.kind == .King {
+					// TODO: Notify board of check
 					return false
 				}
+			}
 
-	package init(color: Color, on position: Square.Position) {
+		}
+		return true
+	}
+
+	internal init(color: Color, on position: Square.Position) {
 		self.color = color
 		self.position = position
 	}

Sources/Engine/Pieces/Rook.swift

@@ -1,31 +1,41 @@
-package class Rook: Piece {
-	package weak var board: Board?
-	package var kind: Kind = .Rook
+internal final class Rook: Piece, LinearMoves {
+	internal weak var board: Board?
+	internal var kind: Kind = .Rook
 
-	package var unicodeRepresentation: String {
+	internal var unicodeRepresentation: String {
 		return color == .Black ? "♜" : "♖"
 	}
-	package var color: Color
+	internal var color: Color
 
-	package var position: Square.Position
+	internal var position: Square.Position
 
-	package var pseudoLegalPositions: [Square.Position] {
-		return []
+	internal var pseudoLegalPositions: [Square.Position] {
+		return getLinearMoves(from: position)
 	}
 
-	package var legalPositions: [Square.Position] {
-		return pseudoLegalPositions.filter { isLegal(pos: $0) }
+	internal var legalPositions: [Square.Position] {
+		return pseudoLegalPositions.filter { isLegal(on: $0) }
 	}
 
-	package func move(dst: Square.Position) -> Bool {
+	internal func move(to dst: Square.Position) -> Bool {
 		return false
 	}
 
-	package func isLegal(pos: Square.Position) -> Bool {
+	internal func isLegal(on pos: Square.Position) -> Bool {
+		if let board = board, let s = board[pos] {
+			if let p = s.piece {
+				if p.color == color { return false }
+				if p.kind == .King {
+					// TODO: Notify board of check
 					return false
 				}
+			}
 
-	package init(color: Color, on position: Square.Position) {
+		}
+		return true
+	}
+
+	internal init(color: Color, on position: Square.Position) {
 		self.color = color
 		self.position = position
 	}

Sources/Engine/Square.swift

@@ -1,12 +1,11 @@
 public struct Square: Equatable {
 
 	public struct Position: Equatable {
-		public let file: UInt8
-		public let rank: UInt8
+		public let file: Int8
+		public let rank: Int8
 
 		public var index: Int {
-			let r = (8 - rank) % 8
-			return Int(8*r+file-1)
+			return Int(8*(8-rank)+file-1)
 		}
 
 		public static func == (lhs: Position, rhs: Position) -> Bool {
@@ -15,8 +14,8 @@ public struct Square: Equatable {
 	}
 
 	public let position: Position
-	public let index: UInt8
-	public var piece: Piece? = nil
+	public let index: Int
+	var piece: Piece? = nil
 	public let color: Color
 
 	public static func == (lhs: Square, rhs: Square) -> Bool {

Sources/exe/main.swift

@@ -3,4 +3,3 @@ import Engine
 let board = Board(fen: .init(fen: "rnbqkb1r/pppppppp/2n5/8/8/8/PPPPPPPP/RNBQKBNR w KQkq - 0 1"))
 // let board: Board = .init()
 print(board)
-