Code as at end of songkick Dojo

langstons-ant/models/ant.js

@@ -1,12 +1,80 @@
 function Ant(world) {
-  this.world = world;
-  this.x = this.y = world.size / 2;
+  with (this) {
+    this.world = world;
+    this.x = this.y = world.size / 2;
+    this.NORTH = 0;
+    this.EAST = 1;
+    this.SOUTH = 2;
+    this.WEST = 3;
+    this.direction = SOUTH;
+
+    this.directions = [
+      function() {
+        y++;
+      },
+      function() {
+        x++;
+      },
+      function() {
+        y--;
+      }, 
+      function() {
+        x--;
+      }
+    ]
+
+    this.black = function() {
+      return {
+        toggleColour: function() {
+          world.paintWhite(x, y)
+        },
+        rotate: function() {
+          direction += 1;
+          if(direction > WEST) {
+            direction = NORTH
+          }  
+        }
+      }
+    }();
+
+    this.white = function() {
+      return {
+        toggleColour: function() {
+          world.paintBlack(x, y)
+        },
+        rotate: function() {
+          direction -= 1;
+          if(direction < NORTH) {
+            direction = WEST
+          }
+        }
+      }
+    }();
+
+    this.currentColour = function() {
+      if (world.isBlack(x,y)) {
+        return black;
+      }
+      else {
+        return white;
+      }
+    }
+
+  }
 }
 
 Ant.prototype.location = function() {
   with (this) return [x, y];
 }
 
 Ant.prototype.step = function() {
-
+  with(this) {
+    currentColour().toggleColour();
+    moveForward();
+    currentColour().rotate();
+  }
+}
+
+Ant.prototype.moveForward = function() {
+  this.directions[this.direction]();
 }

langstons-ant/models/world.js

@@ -1,9 +1,24 @@
 function World(size) {
   this.size = size;
+  this.rows = new Array(size);
+  for (var i = 0; i < this.rows.length; i++) {
+    this.rows[i] = new Array(size);
+  };
 }
 
+World.prototype.isBlack = function(x, y) {
+  return this.rows[x][y] == true;
+}
+
+World.prototype.paintBlack = function(x, y) {
+  this.rows[x][y] = true;
+}
+
+World.prototype.paintWhite = function(x, y) {
+  this.rows[x][y] = false;
+}
+
+
 // TODO:
-// isBlack
-// paintBlack(x,y)
 // paintWhite(x,y)
 // paintAllBlack

langstons-ant/spec/models/ant_spec.js

@@ -1,6 +1,6 @@
 // Rules:
-// White square: paint it black, go left
-// Black square: paint it white, go right
+// White square: paint it black, turn left
+// Black square: paint it white, turn right
 
 Screw.Unit(function() {
 
@@ -21,13 +21,74 @@ Screw.Unit(function() {
       });
 
       it("should move down one square", function() {
-        expect(ant.location()).to(equal, [4, 5]) 
+        expect(ant.location()).to(equal, [5, 4]) 
       });
 
       it("should have painted the square it was on black", function() {
-        expect(world.isBlack(5, 5)).to(be_true) 
+        expect(world.isBlack(5, 5)).to(be_true)
       })
 
+      describe("then a second step", function() {
+        before(function() {
+          ant.step()
+        });
+
+        it("should move right one square", function() {
+          expect(ant.location()).to(equal, [6, 4]);
+        });
+
+        it("should have painted the square it was on black", function() {
+          expect(world.isBlack(5, 4)).to(be_true)
+        });
+
+        describe("then a third step", function() {
+          before(function() {
+            ant.step()
+          });
+
+          it("should move up one square", function() {
+            expect(ant.location()).to(equal, [6, 5]);
+          });
+
+          it("should have painted the square it was on black", function() {
+            expect(world.isBlack(6, 4)).to(be_true)
+          });
+
+          describe("then a fourth step", function() {
+            before(function() {
+              ant.step()
+            });
+
+            it("should move back to square one", function() {
+              expect(ant.location()).to(equal, [5, 5]);
+            });
+
+            it("should have painted the square it was on black", function() {
+              expect(world.isBlack(6, 5)).to(be_true)
+            });
+
+            describe("then a fifth step", function() {
+              before(function() {
+                ant.step()
+              });
+
+              it("should move up one", function() {
+                expect(ant.location()).to(equal, [5, 6]);
+              });
+
+              it("should have painted the square it was on white", function() {
+                expect(world.isBlack(5, 5)).to(be_false)
+              });
+
+            });
+
+          });
+
+
+        });
+
+      });
+
     });
 
     // TODO:

langstons-ant/spec/models/world_spec.js

@@ -0,0 +1,39 @@
+Screw.Unit(function() {
+
+  describe("World", function() {
+    describe("with 2x2 world", function () {
+      before(function() {
+        world = new World(2); 
+      });
+
+      describe("after painting a square black", function() {
+        before(function() {
+          world.paintBlack(0,0);
+        });
+
+        it("should be black", function() {
+          expect(world.isBlack(0,0)).to(be_true);
+        });
+
+        it("another square should be white", function() {
+          expect(world.isBlack(0,1)).to(be_false);
+        });
+
+      });  
+
+    });
+
+    describe("With one square", function() {
+      before(function() {
+        world = new World(1); 
+      });
+
+      it("should start off white", function() {
+        expect(world.isBlack(0,0)).to(be_false);
+      });
+
+    });
+
+  });
+
+});

langstons-ant/spec/suite.html

@@ -24,7 +24,7 @@
     <script src="../models/world.js"></script>
 
     <script src="models/ant_spec.js"></script>
-
+    <script src="models/world_spec.js"></script>
   </head>
   <body></body>
 </html>