diff --git a/views/application.coffee b/views/application.coffee
index 6c1ad59..7632e07 100644
--- a/views/application.coffee
+++ b/views/application.coffee
@@ -1,4 +1,4 @@
-window.Nikoli = Nikoli = {}
+window.Nikoli = {}
 
 class Nikoli.Game
   constructor: (@board, @name, @url) ->
@@ -62,56 +62,50 @@ class Nikoli.Game
   reset: ->
     @generate()
 
+class Nikoli.Cell
+  constructor: (@x, @y, @game) ->
+    @value = @game[@x][@y] if @valid()
+
+  toString: -> "#{@x};#{@y}"
+
+  adjacentCells: ->
+    [
+      new Cell(@x + 1, @y, @game),
+      new Cell(@x - 1, @y, @game),
+      new Cell(@x, @y + 1, @game),
+      new Cell(@x, @y - 1, @game)
+    ]
+
+  valid: (value) ->
+    0 <= @x < @game.length && 0 <= @y < @game[@x].length &&
+      (!value? || value < 0 && @game[@x][@y] < 0 || value >= 0 && @game[@x][@y] >= 0)
+
 class Nikoli.Stream
   constructor: (@game) ->
     @cells = []
 
   calculate: (cell) ->
-    value = @game[cell.x][cell.y]
     @cells = []
-    @type = if value < 0 then 'black' else 'white'
+    @type = if cell.value < 0 then 'black' else 'white'
 
-    cell = {x: cell.x, y: cell.y, value: value}
     cells_to_process = [cell]
 
     while cells_to_process.length > 0
       cell = cells_to_process.pop()
       cells_to_process = cells_to_process.concat @process(cell) unless @include(cell)
 
-
     @cells
 
-  checkCell: (cell, value) ->
-    0 <= cell.x < @game.length && 0 <= cell.y < @game[cell.x].length &&
-      (value < 0 && @game[cell.x][cell.y] < 0 || value >= 0 && @game[cell.x][cell.y] >= 0)
-
   empty: ->
     @cells.length == 0
 
-  getCell: (cell, value) ->
-    {x: cell.x, y: cell.y, value: @game[cell.x][cell.y]} if @checkCell(cell, value)
-
   include: (cell) ->
-    @cells.indexOf("#{cell.x};#{cell.y}") >= 0
+    @cells.indexOf(cell.toString()) >= 0
 
   length: ->
     @cells.length
 
   process: (cell) ->
-    @cells.push("#{cell.x};#{cell.y}")
+    @cells.push(cell.toString())
 
-    x = cell.x
-    y = cell.y
-    value = cell.value
-
-    cells_to_add = []
-    tmp_cell = @getCell({x: x+1, y: y}, value)
-    cells_to_add.push tmp_cell if tmp_cell?
-    tmp_cell = @getCell({x: x-1, y: y}, value)
-    cells_to_add.push tmp_cell if tmp_cell?
-    tmp_cell = @getCell({x: x, y: y+1}, value)
-    cells_to_add.push tmp_cell if tmp_cell?
-    tmp_cell = @getCell({x: x, y: y-1}, value)
-    cells_to_add.push tmp_cell if tmp_cell?
-
-    cells_to_add
+    cell.adjacentCells().filter((adj_cell) -> adj_cell.valid(cell.value))
diff --git a/views/hitori.coffee b/views/hitori.coffee
index 2046400..82f558c 100644
--- a/views/hitori.coffee
+++ b/views/hitori.coffee
@@ -11,23 +11,16 @@ class Nikoli.Hitori extends Nikoli.Game
     for i in [0...solution.length]
       row = solution[i]
       for j in [0...row.length]
-        cell = solution[i][j]
+        cell = new Nikoli.Cell(i, j, solution)
 
-        if cell >= 0
-          white_stream.calculate({x: i, y: j}) if white_stream.empty()
+        if cell.value >= 0
+          white_stream.calculate(cell) if white_stream.empty()
 
-          if !white_stream.include({x: i, y: j})
+          if !white_stream.include(cell)
             errors.push {row: i, column: j, message: 'The stream must be continuous'}
           # TODO check for duplicates in rows and columns
         else
-          adjacent_cells = [
-            {x: i+1, y: j},
-            {x: i-1, y: j},
-            {x: i, y: j+1},
-            {x: i, y: j-1}
-          ]
-          if adjacent_cells.some((el) ->
-            0 <= el.x < solution.length && 0 <= el.y < solution[el.x].length && solution[el.x][el.y] == -1)
+          if cell.adjacentCells().some((adj_cell) -> adj_cell.valid(-1))
             errors.push {row: i, column: j, message: 'Adjacent filled-in cells'}
 
     errors
diff --git a/views/nurikabe.coffee b/views/nurikabe.coffee
index 999ce27..c0856a5 100644
--- a/views/nurikabe.coffee
+++ b/views/nurikabe.coffee
@@ -5,28 +5,28 @@ class Nikoli.Nurikabe extends Nikoli.Game
   errors: ->
     solution = @toArray()
     errors = []
-    processed_cells = []
     black_stream = new Nikoli.Stream(solution)
     white_walls = []
 
     for i in [0...solution.length]
       row = solution[i]
       for j in [0...row.length]
-        cell = solution[i][j]
+        cell = new Nikoli.Cell(i, j, solution)
 
-        if cell < 0
+        if cell.value < 0
           if black_stream.empty()
-            black_stream.calculate({x: i, y: j})
-          else if !black_stream.include({x: i, y: j})
+            black_stream.calculate(cell)
+          else if !black_stream.include(cell)
             errors.push {row: i, column: j, message: 'The stream must be continuous'}
-        else if cell > 0
-          if white_walls.some((wall) -> wall.include({x: i, y: j}))
+          # TODO check for pools
+        else if cell.value > 0
+          if white_walls.some((wall) -> wall.include(cell))
             errors.push {row: i, column: j, message: 'Each wall must contain exactly one numbered cell.'}
           else
             wall = new Nikoli.Stream(solution)
-            wall.calculate({x: i, y: j})
+            wall.calculate(cell)
 
-            if wall.length() != cell
+            if wall.length() != cell.value
               errors.push {row: i, column: j, message: 'Each numbered cell is a wall cell, the number in it is the number of cells in that wall.'}
 
             white_walls.push(wall)