Merged in better-communication (pull request #49)

Better communication

Shogi.Domain/Pieces/Rook.cs

@@ -0,0 +1,52 @@
+using Shogi.Domain.Pathing;
+using System.Collections.ObjectModel;
+
+namespace Shogi.Domain.Pieces
+{
+	public sealed class Rook : Piece
+	{
+		public static readonly ReadOnlyCollection<Path> Player1Paths = new(new List<Path>(4)
+		{
+			new Path(Direction.Up, Distance.MultiStep),
+			new Path(Direction.Left, Distance.MultiStep),
+			new Path(Direction.Right, Distance.MultiStep),
+			new Path(Direction.Down, Distance.MultiStep)
+		});
+
+		private static readonly ReadOnlyCollection<Path> PromotedPlayer1Paths = new(new List<Path>(8)
+		{
+			new Path(Direction.Up, Distance.MultiStep),
+			new Path(Direction.Left, Distance.MultiStep),
+			new Path(Direction.Right, Distance.MultiStep),
+			new Path(Direction.Down, Distance.MultiStep),
+			new Path(Direction.UpLeft),
+			new Path(Direction.UpRight),
+			new Path(Direction.DownLeft),
+			new Path(Direction.DownRight)
+		});
+
+		public static readonly ReadOnlyCollection<Path> Player2Paths =
+			Player1Paths
+			.Select(m => m.Invert())
+			.ToList()
+			.AsReadOnly();
+
+		public static readonly ReadOnlyCollection<Path> Player2PromotedPaths =
+			PromotedPlayer1Paths
+			.Select(m => m.Invert())
+			.ToList()
+			.AsReadOnly();
+
+		public Rook(WhichPlayer owner, bool isPromoted = false)
+			: base(WhichPiece.Rook, owner, isPromoted)
+		{
+		}
+
+		public override ReadOnlyCollection<Path> MoveSet => Owner switch
+		{
+			WhichPlayer.Player1 => IsPromoted ? PromotedPlayer1Paths : Player1Paths,
+			WhichPlayer.Player2 => IsPromoted ? Player2PromotedPaths : Player2Paths,
+			_ => throw new NotImplementedException(),
+		};
+	}
+}