Change Game#index to Game#index_of to unshadow previous def

the method #index is defined by the enumerable module, and caused type confusion

spec/lx_chess/board_spec.cr

@@ -26,4 +26,11 @@ describe LxChess::Board do
       board.border_right(12).should eq(15)
     end
   end
+
+  describe "#index" do
+    it "returns the index of a coordinate" do
+      board = LxChess::Board.new
+      board.index_of("e2").should eq(12)
+    end
+  end
 end

spec/lx_chess/game/parse_san_spec.cr

@@ -13,8 +13,8 @@ describe Game do
         game = Game.new
         game.board["e2"] = Piece.from_fen('P')
         from, to = game.parse_san("e4")
-        from.should eq(game.board.index("e2"))
-        to.should eq(game.board.index("e4"))
+        from.should eq(game.board.index_of("e2"))
+        to.should eq(game.board.index_of("e4"))
       end
 
       it "disambiguates the move correctly" do
@@ -27,7 +27,7 @@ describe Game do
 
         moves = game.parse_san("dxe5")
         debug_board(game, moves)
-        moves.should eq(["d4", "e5"].map { |s| game.board.index(s) })
+        moves.should eq(["d4", "e5"].map { |s| game.board.index_of(s) })
       end
     end
   end

spec/spec_helper.cr

@@ -5,11 +5,11 @@ require "../src/lx_chess/board"
 require "../src/lx_chess/term_board"
 
 def debug_board(game : LxChess::Game, moves : Array(String))
-  moves = moves.map { |m| game.board.index(m) }
+  moves = moves.map { |m| game.board.index_of(m) }
   debug_board(game, moves)
 end
 
-def debug_board(game : LxChess::Game, moves = [] of Int16)
+def debug_board(game : LxChess::Game, moves : Array(Int16) = [] of Int16)
   puts
   gb = LxChess::TermBoard.new(game.board)
   gb.highlight(moves)

src/lx_chess/board.cr

@@ -38,12 +38,12 @@ module LxChess
 
     # Retrieve a piece at a human cord ex: `a1`
     def [](cord : String)
-      self[index(cord)]
+      self[index_of(cord)]
     end
 
     # Retrieve a piece at an *x* and *y* cord
     def at(x : Int, y : Int)
-      self[index(x, y)]
+      self[index_of(x, y)]
     end
 
     def rel_index(index : Int, x : Int, y : Int)
@@ -58,21 +58,21 @@ module LxChess
 
     # Set a piece on the board at a certain human readable *cord*
     def []=(cord : String, piece : Piece | Nil)
-      self[index(cord)] = piece
+      self[index_of(cord)] = piece
     end
 
     # Convert an *x* and *y* position into an index.
     # Ex: `4, 4` => `36`
-    def index(x : Int, y : Int)
+    def index_of(x : Int, y : Int)
       ((y * @width) + x).to_i16
     end
 
     # Convert human *cord* into an index on the board.
     # Ex: `a1` => `0`
-    def index(cord : String)
+    def index_of(cord : String)
       x = LETTERS.index(cord[0].downcase) || 0
       y = cord[1].to_i - 1
-      index(x, y)
+      index_of(x, y)
     end
 
     # Convert an *index* into a human coordinate (ex: `a1`)

src/lx_chess/game.cr

@@ -52,7 +52,7 @@ module LxChess
 
     def en_passant_target=(cord : String)
       if cord =~ /[a-z]+\d+/
-        @en_passant_target = @board.index(cord)
+        @en_passant_target = @board.index_of(cord)
       else
         @en_passant_target = nil
       end
@@ -63,7 +63,7 @@ module LxChess
     end
 
     def en_passant_target=(cord : String)
-      @en_passant_target = @board.index(cord)
+      @en_passant_target = @board.index_of(cord)
     end
 
     def full_moves
@@ -85,7 +85,7 @@ module LxChess
 
     # Parse standard algebraic notation
     def parse_san(notation : Notation)
-      index = @board.index(notation.square)
+      index = nil
 
       if notation.castles?
         raise "expected to find a king, but couldn't!" unless king = find_king
@@ -103,6 +103,12 @@ module LxChess
         end
       end
 
+      if square = notation.square
+        index = @board.index_of(square)
+      end
+
+      raise "Missing index" unless index
+
       fen_symbol = notation.fen_symbol(@turn == 0 ? "w" : "b")
 
       move_sets = @board.map do |piece|
@@ -134,14 +140,14 @@ module LxChess
       raise SanError.new("#{notation.to_s} is ambiguous") if move_sets.size > 1
       if set = move_sets.first?
         # from, to
-        [set.piece.index.as(Int16), index.as(Int16)]
+        [set.piece.index, index]
       else
         raise SanError.new("no moves matching `#{notation.to_s}`")
       end
     end
 
     def move_to_san(from : String, to : String, promotion : Char? = nil, turn = @turn)
-      move_to_san(@board.index(from), @board.index(to), promotion, turn)
+      move_to_san(@board.index_of(from), @board.index_of(to), promotion, turn)
     end
 
     def move_to_san(from : Int, to : Int, promotion : Char? = nil, turn = @turn)
@@ -296,7 +302,6 @@ module LxChess
       return false unless player.castle_king
       return false unless index = piece.index
       return false unless (index - @board.border_left(index)).abs >= 2
-      # TODO: figure out if castling crosses checks
       @board[index + 1].nil? && @board[index + 2].nil?
     end
 
@@ -306,12 +311,11 @@ module LxChess
       return false unless player.castle_queen
       return false unless index = piece.index
       return false unless (index - @board.border_left(index)).abs >= 2
-      # TODO: figure out if castling crosses checks
       @board[index - 1].nil? && @board[index - 2].nil?
     end
 
     def tmp_move(from : String, to : String, promotion : Char? = nil)
-      tmp_move(@board.index(from), @board.index(to), promotion) do
+      tmp_move(@board.index_of(from), @board.index_of(to), promotion) do
         yield
       end
     end
@@ -334,7 +338,7 @@ module LxChess
     end
 
     def make_move(from : String, to : String, promotion : Char? = nil)
-      make_move(from: @board.index(from), to: @board.index(to), promotion: promotion)
+      make_move(from: @board.index_of(from), to: @board.index_of(to), promotion: promotion)
     end
 
     # Make a move given a set of coordinates
@@ -368,7 +372,7 @@ module LxChess
               p && p.color == piece.color && p.rook? && p.index.as(Int16) > piece.index.as(Int16)
             end
             if rook
-              @board.move(from: rook.index.as(Int16), to: to - 1)
+              @board.move(from: rook.index, to: to - 1)
             end
           else
             tmp_move(from, to + 1) do
@@ -379,7 +383,7 @@ module LxChess
               p && p.color == piece.color && p.rook? && p.index.as(Int16) < piece.index.as(Int16)
             end
             if rook
-              @board.move(from: rook.index.as(Int16), to: to + 1)
+              @board.move(from: rook.index, to: to + 1)
             end
           end
         end

src/lx_chess/term_board.cr

@@ -73,7 +73,7 @@ module LxChess
         io << (y + 1).to_s.rjust(3) << ": "
 
         files.each do |x|
-          index = @board.index(x, y)
+          index = @board.index_of(x, y)
           piece = @board[index]
 
           tint = (index + y) % 2 == 0 ? :light : :dark

src/lx_chess/term_game.cr

@@ -38,7 +38,7 @@ module LxChess
       when /moves\s+([a-z]\d)/i
         if matches = input.match(/[a-z]\d/i)
           if square = matches[0]?
-            if index = @game.board.index(square)
+            if index = @game.board.index_of(square)
               if set = @game.moves(index)
                 @gb.highlight(set.moves, "blue")
                 from = "#{set.piece.fen_symbol}#{@game.board.cord(index)}: "
@@ -83,7 +83,7 @@ module LxChess
               san = @game.move_to_san(from, to, promo)
               @game.make_move(from, to, promo)
               @pgn.history << san
-              @gb.highlight([@game.board.index(from), @game.board.index(to)])
+              @gb.highlight([@game.board.index_of(from), @game.board.index_of(to)])
               @log.unshift "#{san.to_s}: #{from} => #{to}"
             end
           end