Changed visibility from package to interal

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