Added commands to execute interactively

Sources/Engine/Board.swift

@@ -6,6 +6,7 @@ protocol EventDelegate {
 	func notify(_ event: Event)
 	func movePiece(_ piece: Piece, to dst: Square.Position) throws
 	func addPieceToTarget(_ piece: Piece, target: Square.Position)
+	func getSquareInfo(on pos: Square.Position) -> Square?
 }
 public class Board: CustomStringConvertible, EventDelegate {
 	public typealias Grid = [[Square]]
@@ -21,6 +22,56 @@ public class Board: CustomStringConvertible, EventDelegate {
 		}
 	}
 
+	public struct TerminalColors: CustomStringConvertible, Hashable {
+		public enum Foreground: String {
+			case def = "39"
+			case black = "30"
+			case red = "31"
+			case green = "32"
+			case yellow = "33"
+			case blue = "34"
+			case magenta = "35"
+			case cyan = "36"
+			case white = "37"
+		}
+		public enum Background: String {
+			case def = "49"
+			case black = "40"
+			case red = "41"
+			case green = "42"
+			case yellow = "43"
+			case blue = "44"
+			case magenta = "45"
+			case cyan = "46"
+			case white = "47"
+		}
+
+		public var foregroundColor: Foreground? = .def
+		public var backgroundColor: Background? = .def
+
+		public init() {}
+
+		public init(fg: Foreground?, bg: Background) {
+			foregroundColor = fg
+			backgroundColor = bg
+		}
+
+		public var description: String {
+			var res = "\u{001B}["
+			if let fc = foregroundColor {
+				res += fc.rawValue
+				if backgroundColor != nil {
+					res += ";"
+				}
+			}
+			if let bc = backgroundColor {
+				res += bc.rawValue
+			}
+			return res + "m"
+		}
+
+	}
+
 	func notify(_ event: Event) {
 
 	}
@@ -38,10 +89,11 @@ public class Board: CustomStringConvertible, EventDelegate {
 		halfMoveClock / 2
 	}
 
-	internal var threatenedSquares: [Color: Set<Square.Position>] = [
-		.White: [],
-		.Black: [],
-	]
+	public internal(set) var threatenedSquares: [Color: Set<Square.Position>] =
+		[
+			.White: [],
+			.Black: [],
+		]
 
 	public internal(set) var history = History()
 
@@ -79,7 +131,7 @@ public class Board: CustomStringConvertible, EventDelegate {
 			case .destinationSquareUnreachable(let pos):
 				"The destination square given \(pos.rank) \(pos.file) is unreachable."
 			case .squareHasNoPiece(let pos):
-				"The square \(pos.rank) \(pos.file) doesn't have any piece to be moved."
+				"The square \(pos.rank) \(pos.file) doesn't have any piece."
 			case .destinationIsIllegal(let pos):
 				"The destination square given \(pos.rank) \(pos.file) is illegal to be moved to."
 			case .squareANIsTooLong(let an):
@@ -106,7 +158,7 @@ public class Board: CustomStringConvertible, EventDelegate {
 		guard let f1 = src.first, let r1 = src.last, r1.isWholeNumber else {
 			return
 		}
-		guard let f2 = dst.first, let r2 = src.last, r2.isWholeNumber else {
+		guard let f2 = dst.first, let r2 = dst.last, r2.isWholeNumber else {
 			return
 		}
 		guard
@@ -245,7 +297,9 @@ public class Board: CustomStringConvertible, EventDelegate {
 		do {
 			try setBoard()
 			for square in squares where square.piece != nil {
-				square.piece?.getLegalPosition()
+				let p = square.piece!
+				p.getLegalPosition()
+				threatenedSquares[p.color]! += Set(p.legalPositions)
 			}
 		} catch Fen.FenError.NotAppropriateLength(let n, let column) {
 			fatalError("Not appropriate length: \(n) on \(column)")
@@ -254,15 +308,29 @@ public class Board: CustomStringConvertible, EventDelegate {
 		}
 	}
 
-	public var description: String {
+	public func text(with colors: [TerminalColors: [Square.Position]]? = nil)
+		-> String
+	{
 		var boardString =
 			"    A   B   C   D   E   F   G   H \n  \(UnicodeBar.TopHorizontalLine)\n"
 		var _rank: UInt8 = 8
+		let def: TerminalColors = .init()
+		var h1 = def
 		board.forEach { rank in
 			boardString += String(_rank) + " \(UnicodeBar.VerticalBar)"
 			rank.forEach { square in
 				let p = square.piece?.unicodeRepresentation ?? " "
-				boardString += " \(p) \(UnicodeBar.VerticalBar)"
+				if let c = colors {
+					for (color, s) in c {
+						h1 = def
+						if (s.contains { $0 == square.position }) {
+							h1 = color
+							break
+						}
+					}
+				}
+				boardString +=
+					"\(h1) \(p) \(def)\(UnicodeBar.VerticalBar)"
 			}
 			boardString += "\n"
 			_rank -= 1
@@ -274,6 +342,10 @@ public class Board: CustomStringConvertible, EventDelegate {
 		return boardString
 	}
 
+	public var description: String {
+		text()
+	}
+
 	internal subscript(pos: Square.Position) -> Square? {
 		guard let i = pos.index else {
 			return nil

Sources/Engine/Pieces/King.swift

@@ -2,7 +2,7 @@ final class King: Piece {
 	typealias Threats = (Piece?, Piece?)
 	var threats: Threats = (nil, nil)
 	override var unicodeRepresentation: String {
-		return color == .Black ? "♛" : "♕"
+		return color == .Black ? "♚" : "♔"
 	}
 
 	override var pseudoLegalPositions: [Square.Position] {

Sources/Engine/Pieces/Piece.swift

@@ -55,7 +55,6 @@ public enum Kind: String, CaseIterable {
 
 public class Piece: Hashable {
 	#warning("TODO: To be removed, handle everything through the delegate")
-	internal weak var board: Board?
 	public internal(set) var color: Color
 	public internal(set) var halfMoveCount: UInt8 = 0
 	public var unicodeRepresentation: String {
@@ -73,7 +72,7 @@ public class Piece: Hashable {
 	internal var delegate: EventDelegate?
 
 	internal func move(to dst: Square.Position) throws {
-		if !(legalPositions.contains { $0 == dst }) {
+		guard (legalPositions.contains { $0 == dst }) else {
 			throw Board.MoveFailure.destinationIsIllegal(pos: dst)
 		}
 
@@ -83,7 +82,7 @@ public class Piece: Hashable {
 
 	#warning("This method should be better thought out.")
 	internal func isLegal(on pos: Square.Position) -> Bool {
-		if let board = board, let s = board[pos] {
+		if let s = delegate?.getSquareInfo(on: pos) {
 			if let p = s.piece {
 				if p.color == color { return false }
 				if let king = p as? King {