Add diagonal and metaboard checking.

.gitignore

@@ -0,0 +1,42 @@
+
+# Created by https://www.gitignore.io/api/nim,visualstudiocode
+# Edit at https://www.gitignore.io/?templates=nim,visualstudiocode
+
+### Nim ###
+nimcache/
+
+### VisualStudioCode ###
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+### VisualStudioCode Patch ###
+# Ignore all local history of files
+.history
+
+# End of https://www.gitignore.io/api/nim,visualstudiocode
+
+
+# Created by https://www.gitignore.io/api/nim,visualstudiocode
+# Edit at https://www.gitignore.io/?templates=nim,visualstudiocode
+
+### Nim ###
+nimcache/
+
+### VisualStudioCode ###
+.vscode/*
+!.vscode/settings.json
+!.vscode/tasks.json
+!.vscode/launch.json
+!.vscode/extensions.json
+
+# Ignore all
+*
+
+# Unignore all with extensions
+!*.*
+
+# Unignore all dirs
+!*/

src/libmttt.nim

@@ -1,7 +1,39 @@
-import sets
+import sets, strformat, options
 
-include libmttt/types
-include libmttt/checks
+type
+  ## A game board is a simple 2 dimensional array.
+  ## Markers of any type can be placed inside the cells
+  Board*[T] = array[3, array[3, T]]
+
+  Player* = ref object
+    mark*: Mark
+    name*: string
+
+  Mark* = enum
+    mPlayer1, ## The mark of the fist player
+    mPlayer2, ## The mark of the second player
+    mFree,    ## This mark signals that a cell is empty
+    mDraw     ## Special mark to indicate the game has ended in a draw
+
+  GameState* = ref object
+    ## Contains all state for a pint in the game
+    board*: Board[Board[Mark]]
+    players*: array[2, Player]
+    currentPlayer*: Player
+    currentBoard*: Option[(int, int)]
+    result*: Mark
+    turn*: int
+
+proc `$`*(player: Player): string = 
+  $player.name
+
+proc `$`*(game: GameState): string = 
+  &"""
+  Game is in turn {$game.turn}
+  Players are: '{$game.players[0]}' and '{$game.players[1]}'
+  Current player: '{$game.currentPlayer}'
+  Game state is: {$game.result}
+  """
 
 proc newBoard[T](initial: T): Board[T] =
   ## Create a new game board filled with the initial value
@@ -24,10 +56,59 @@ proc newGame*(player1, player2: Player): GameState =
   GameState(
     players: [player1, player2],
     currentPlayer: player1,
-    result: rOpen,
+    result: mFree,
     board: newMetaBoard(mFree))
 
-proc checkBoard*(board: Board[Mark]): BoardResult =
+###################################################
+# Board Checking
+###################################################
+
+proc selectResult(states: HashSet[Mark]): Mark =
+  ## Analyse a set of results and select the correct one
+  if states.contains(mPlayer1) and
+      states.contains(mPlayer2):
+      raise newException(Exception, "Both players cannot win at the same time")
+
+  if states.contains(mPlayer1):
+    return mPlayer1
+  if states.contains(mPlayer2):
+    return mPlayer2
+  if states.contains(mFree):
+    return mFree
+  return mDraw
+
+proc checkRow(row: array[3, Mark]): Mark =
+  var tokens = toHashSet(row)
+  # A player has won
+  if tokens.len == 1 and not tokens.contains(mFree):
+    return tokens.pop()
+  # The row is full
+  if tokens.len == 2 and not tokens.contains(mFree):
+    return mDraw
+  # There are still cells free in this row
+  return mFree
+
+proc checkRows(board: Board[Mark]): Mark =
+  ## Iterate over all rows of this board and return the result.
+  var states: HashSet[Mark]
+  states.init()
+  for row in board:
+    states.incl(checkRow(row))
+  return states.selectResult()
+
+proc checkDiagonals(board: Board[Mark]): Mark =
+  var states: HashSet[Mark]
+  states.init()
+  var topToBottom: array[3, Mark]
+  var bottomToTop: array[3, Mark]
+  for x in 0 .. 2:
+    topToBottom[x] = board[x][x]
+    bottomToTop[x] = board[2-x][x]
+  states.incl(checkRow(topToBottom))
+  states.incl(checkRow(bottomToTop))
+  return states.selectResult()
+
+proc checkBoard*(board: Board[Mark]): Mark =
   ## Perform a check on a single sub board to see its result
 
   # Create a seconded, transposed board.
@@ -37,13 +118,23 @@ proc checkBoard*(board: Board[Mark]): BoardResult =
       for y in 0 .. 2:
         transposed[x][y] = board[y][x]
 
-  var states: HashSet[BoardResult]
-  states.init()    
+  var states: HashSet[Mark]
+  states.init()
+  states.incl(checkDiagonals(board))
   for b in [board, transposed]:
     states.incl(checkRows(b))
+
   return selectResult(states)
     
 
-proc checkBoard*(board: Board[Board[Mark]]): BoardResult =
+proc checkBoard*(board: Board[Board[Mark]]): Mark =
   ## Perform a check on a metaboard to see the overall game result
-  rOpen
+
+  # This temporary board will hold the intermediate results from each sub board
+  var subResults = newBoard(mFree)
+  var states: HashSet[Mark]
+  states.init()
+  for x in 0 .. 2:
+    for y in 0 .. 2:
+      subResults[x][y] = checkBoard(board[x][y])
+  return checkBoard(subResults)

src/libmttt/checks.nim

@@ -1,42 +0,0 @@
-import sets
-
-import types
-
-proc selectResult(states: HashSet[BoardResult]): BoardResult =
-  ## Analyse a set of results and select the correct one
-  if states.contains(rPlayer1) and
-      states.contains(rPlayer2):
-      raise newException(Exception, "Both players cannot win at the same time")
-
-  if states.contains(rPlayer1):
-    return rPlayer1
-  if states.contains(rPlayer2):
-    return rPlayer2
-  if states.contains(rOpen):
-    return rOpen
-  return rDraw
-
-proc checkRow(row: array[3, Mark]): BoardResult =
-  var tokens = toHashSet(row)
-  # A player has won
-  if tokens.len == 1 and not tokens.contains(mFree):
-    let rowResult = tokens.pop()
-    if rowResult == mPlayer1:
-      return rPlayer1
-    else:
-      return rPlayer2
-  # The row is full
-  if tokens.len == 2 and not tokens.contains(mFree):
-    return rDraw
-  # There are still cells free in this row
-  else:
-    return rOpen
-
-proc checkRows(board: Board[Mark]): BoardResult =
-  ## Iterate over all rows of this board and return the result.
-  var states: HashSet[BoardResult]
-  states.init()
-  for row in board:
-    states.incl(checkRow(row))
-  return states.selectResult()
-  

src/libmttt/types.nim

@@ -1,39 +0,0 @@
-import strformat
-type
-  ## A game board is a simple 2 dimensional array.
-  ## Markers of any type can be placed inside the cells
-  Board*[T] = array[3, array[3, T]]
-
-  Player* = ref object
-    mark*: Mark
-    name*: string
-
-  Mark* = enum
-    mPlayer1, ## The mark of the fist player
-    mPlayer2, ## The mark of the second player
-    mFree     ## This mark signals that a cell is empty
-
-  BoardResult* = enum
-    rPlayer1, ## The first player has won the board
-    rPlayer2, ## The second player has won the board
-    rDraw,    ## There is no winner. The board has ended in a draw
-    rOpen     ## The game on this board is still ongoing
-
-  GameState* = ref object
-    ## Contains all state for a pint in the game
-    board*: Board[Board[Mark]]
-    players*: array[2, Player]
-    currentPlayer*: Player
-    result*: BoardResult
-    turn*: int
-
-proc `$`*(player: Player): string = 
-  $player.name
-
-proc `$`*(game: GameState): string = 
-  &"""
-  Game is in turn {$game.turn}
-  Players are: '{$game.players[0]}' and '{$game.players[1]}'
-  Current player: '{$game.currentPlayer}'
-  Game state is: {$game.result}
-  """

tests/test1.nim

@@ -1,49 +0,0 @@
-# This is just an example to get you started. You may wish to put all of your
-# tests into a single file, or separate them into multiple `test1`, `test2`
-# etc. files (better names are recommended, just make sure the name starts with
-# the letter 't').
-#
-# To run these tests, simply execute `nimble test`.
-
-import unittest
-
-import libmttt
-
-suite "Test the board result checker":
-  setup:
-    var
-      player1 = Player(name: "Max")
-      player2 = Player(name: "Adam")
-      state: GameState = newGame(player1, player2)
-
-  test "row checking":    
-    state.board[0][0] = [
-      [mFree, mFree, mFree],
-      [mPlayer1, mPlayer1, mPlayer1],
-      [mFree, mFree, mFree]
-    ]
-    check checkBoard(state.board[0][0]) == rPlayer1
-
-  test "column checking":      
-    state.board[0][0] = [
-      [mPlayer2, mFree, mPlayer1],
-      [mPlayer2, mPlayer1, mFree],
-      [mPlayer2, mPlayer1, mFree]
-    ]
-    check checkBoard(state.board[0][0]) == rPlayer2
-
-  test "check for draw":      
-    state.board[0][0] = [
-      [mPlayer1, mPlayer2, mPlayer1],
-      [mPlayer2, mPlayer1, mPlayer1],
-      [mPlayer2, mPlayer1, mPlayer2]
-    ]
-    check checkBoard(state.board[0][0]) == rDraw
-
-  test "check for open board":      
-    state.board[0][0] = [
-      [mPlayer1, mPlayer2, mFree],
-      [mPlayer1, mFree, mPlayer1],
-      [mFree, mPlayer1, mPlayer2]
-    ]
-    check checkBoard(state.board[0][0]) == rOpen

tests/testChecks.nim

@@ -0,0 +1,159 @@
+# This is just an example to get you started. You may wish to put all of your
+# tests into a single file, or separate them into multiple `test1`, `test2`
+# etc. files (better names are recommended, just make sure the name starts with
+# the letter 't').
+#
+# To run these tests, simply execute `nimble test`.
+
+import unittest
+
+import libmttt
+
+suite "Test the board result checker":
+  setup:
+    var
+      player1 = Player(name: "Max")
+      player2 = Player(name: "Adam")
+      state: GameState = newGame(player1, player2)
+
+  test "winning row":    
+    state.board[0][0] = [
+      [mFree, mFree, mFree],
+      [mPlayer1, mPlayer1, mPlayer1],
+      [mFree, mFree, mFree]
+    ]
+    check checkBoard(state.board[0][0]) == mPlayer1
+
+  test "winning column":      
+    state.board[0][0] = [
+      [mPlayer2, mFree, mPlayer1],
+      [mPlayer2, mPlayer1, mFree],
+      [mPlayer2, mPlayer1, mFree]
+    ]
+    check checkBoard(state.board[0][0]) == mPlayer2
+
+  test "winning diagonals":      
+    state.board[0][0] = [
+      [mFree, mFree, mPlayer2],
+      [mFree, mPlayer2, mFree],
+      [mPlayer2, mFree, mFree]
+    ]
+    check(checkBoard(state.board[0][0]) == mPlayer2)
+
+    state.board[0][0] = [
+      [mPlayer1, mPlayer2, mPlayer2],
+      [mPlayer2, mPlayer1, mPlayer1],
+      [mPlayer2, mFree, mPlayer1]
+    ]
+    check(checkBoard(state.board[0][0]) == mPlayer1)
+
+  test "board is a draw":      
+    state.board[0][0] = [
+      [mPlayer1, mPlayer2, mPlayer1],
+      [mPlayer2, mPlayer1, mPlayer1],
+      [mPlayer2, mPlayer1, mPlayer2]
+    ]
+    check checkBoard(state.board[0][0]) == mDraw
+
+  test "board is open":      
+    state.board[0][0] = [
+      [mPlayer1, mPlayer2, mFree],
+      [mPlayer1, mFree, mPlayer1],
+      [mFree, mPlayer1, mPlayer2]
+    ]
+    check checkBoard(state.board[0][0]) == mFree
+
+  test "free inital metaboard":
+    check checkBoard(state.board) == mFree
+  
+  test "winning metaboard row":
+    state.board[1][0] = [
+      [mPlayer1, mPlayer2, mFree],
+      [mPlayer1, mPlayer1, mPlayer1],
+      [mFree, mPlayer1, mPlayer2]
+    ]
+    state.board[1][1] = [
+      [mFree, mFree, mPlayer1],
+      [mFree, mPlayer1, mFree],
+      [mPlayer1, mFree, mFree]
+    ]
+    state.board[1][2] = [
+      [mFree, mFree, mPlayer1],
+      [mFree, mFree, mPlayer1],
+      [mFree, mFree, mPlayer1]
+    ]
+    check checkBoard(state.board) == mPlayer1
+
+  test "winning metaboard column":
+    state.board[0][1] = [
+      [mPlayer1, mPlayer2, mFree],
+      [mPlayer1, mPlayer1, mPlayer1],
+      [mFree, mPlayer1, mPlayer2]
+    ]
+    state.board[1][1] = [
+      [mFree, mFree, mFree],
+      [mPlayer1, mPlayer1, mPlayer1],
+      [mFree, mFree, mFree]
+    ]
+    state.board[2][1] = [
+      [mPlayer1, mFree, mFree],
+      [mPlayer1, mFree, mFree],
+      [mPlayer1, mFree, mFree]
+    ]
+    check checkBoard(state.board) == mPlayer1
+
+  test "winning metaboard diagonal":
+    state.board[0][0] = [
+      [mPlayer2, mPlayer2, mFree],
+      [mPlayer2, mPlayer2, mPlayer2],
+      [mFree, mPlayer2, mPlayer2]
+    ]
+    state.board[1][1] = [
+      [mFree, mFree, mFree],
+      [mPlayer2, mPlayer2, mPlayer2],
+      [mFree, mFree, mFree]
+    ]
+    state.board[2][2] = [
+      [mPlayer2, mFree, mFree],
+      [mPlayer2, mFree, mFree],
+      [mPlayer2, mFree, mFree]
+    ]
+    check checkBoard(state.board) == mPlayer2
+
+  test "winning metaboard with some boards in draw":
+    let winner = [
+      [mFree, mFree, mFree],
+      [mPlayer2, mPlayer2, mPlayer2],
+      [mFree, mFree, mFree]
+    ]
+    let drawn =  [
+      [mPlayer2, mPlayer2, mPlayer1],
+      [mPlayer1, mPlayer1, mPlayer2],
+      [mPlayer2, mPlayer1, mPlayer2]
+    ]
+    state.board[0][0] = winner
+    state.board[1][1] = winner
+    state.board[2][2] = winner
+    state.board[1][0] = drawn
+    state.board[2][0] = drawn
+    check checkBoard(state.board) == mPlayer2
+    
+  test "metaboard is drawn":
+    let drawn =  [
+      [mPlayer2, mPlayer2, mPlayer1],
+      [mPlayer1, mPlayer1, mPlayer2],
+      [mPlayer2, mPlayer1, mPlayer2]
+    ]
+    for x in 0 .. 2:
+      for y in 0 .. 2:
+        state.board[x][y] = drawn
+    check checkBoard(state.board) == mDraw
+
+  test "illegal situation: both players win board":
+    state.board[1][1] = [
+      [mPlayer1, mPlayer1, mPlayer1],
+      [mPlayer2, mPlayer2, mPlayer2],
+      [mFree, mFree, mFree]
+    ]
+    expect(Exception):
+      discard checkBoard(state.board)