Merge pull request #1 from mariancerny/master

Added #18 Game of Life in Objective C.

Author: jirkapenzes

018-objective-c/DLCell.h

@@ -0,0 +1,19 @@
+//
+//  DLCell.h
+//  CodingDojo18
+//
+//  Created by Marián Černý on 31.07.14.
+//  Copyright (c) 2014 Pematon, s.r.o. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface DLCell : NSObject
+
+@property (assign, nonatomic) BOOL alive;
+
+- (instancetype)initWithAlive:(BOOL)alive; // designated initializer
+
+- (BOOL)shouldBeDeadInNextGenerationWithNeighboursCount:(NSInteger)neighboursCount;
+
+@end

018-objective-c/DLCell.m

@@ -0,0 +1,36 @@
+//
+//  DLCell.m
+//  CodingDojo18
+//
+//  Created by Marián Černý on 31.07.14.
+//  Copyright (c) 2014 Pematon, s.r.o. All rights reserved.
+//
+
+#import "DLCell.h"
+
+@implementation DLCell
+
+- (instancetype)initWithAlive:(BOOL)alive
+{
+    self = [super init];
+    if (self) {
+        _alive = alive;
+    }
+    return self;
+}
+
+- (BOOL)shouldBeDeadInNextGenerationWithNeighboursCount:(NSInteger)neighboursCount
+{
+    if (self.alive)
+    {
+        if (neighboursCount > 1 && neighboursCount <= 3) {
+            return NO;
+        }
+
+        return YES;
+    }
+
+    return neighboursCount != 3;
+}
+
+@end

018-objective-c/DLWorld.h

@@ -0,0 +1,13 @@
+//
+//  DLWorld.h
+//  CodingDojo18
+//
+//  Created by Marián Černý on 31.07.14.
+//  Copyright (c) 2014 Pematon, s.r.o. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface DLWorld : NSObject
+
+@end

018-objective-c/DLWorld.m

@@ -0,0 +1,13 @@
+//
+//  DLWorld.m
+//  CodingDojo18
+//
+//  Created by Marián Černý on 31.07.14.
+//  Copyright (c) 2014 Pematon, s.r.o. All rights reserved.
+//
+
+#import "DLWorld.h"
+
+@implementation DLWorld
+
+@end

018-objective-c/GameOfLifeTests.m

@@ -0,0 +1,91 @@
+//
+//  CodingDojo18Tests.m
+//  CodingDojo18Tests
+//
+//  Created by Marián Černý on 31.07.14.
+//  Copyright (c) 2014 Pematon, s.r.o. All rights reserved.
+//
+
+#import <XCTest/XCTest.h>
+
+#import "DLWorld.h"
+#import "DLCell.h"
+
+@interface CodingDojo18Tests : XCTestCase
+
+@end
+
+@implementation CodingDojo18Tests
+
+// Any live cell with fewer than two live neighbours dies, as if caused by under-population.
+// Any live cell with two or three live neighbours lives on to the next generation.
+// Any live cell with more than three live neighbours dies, as if by overcrowding.
+// Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.
+
+
+- (void)cellThatIsAlive:(BOOL)alive withNeighbours:(NSInteger)neighbours shouldDie:(BOOL)shouldDie
+{
+    DLCell *cell = [[DLCell alloc] initWithAlive:alive];
+    XCTAssertEqual([cell shouldBeDeadInNextGenerationWithNeighboursCount:neighbours], shouldDie, @"Alive cell %d with %d neighbours should die %d", (int)alive, (int)neighbours, (int)shouldDie);
+}
+
+- (void)aliveCellWithNeighbours:(NSInteger)neighbours shouldDie:(BOOL)shouldDie
+{
+    [self cellThatIsAlive:YES withNeighbours:neighbours shouldDie:shouldDie];
+}
+
+- (void)deadCellWithNeighbours:(NSInteger)neighbours shouldDie:(BOOL)shouldDie
+{
+    [self cellThatIsAlive:NO withNeighbours:neighbours shouldDie:shouldDie];
+}
+
+// Any live cell with fewer than two live neighbours dies, as if caused by under-population.
+- (void)testUnderPopulation
+{
+    [self aliveCellWithNeighbours:0 shouldDie:YES];
+    [self aliveCellWithNeighbours:1 shouldDie:YES];
+}
+
+// Any live cell with two or three live neighbours lives on to the next generation.
+- (void)testSurvival
+{
+    [self aliveCellWithNeighbours:2 shouldDie:NO];
+    [self aliveCellWithNeighbours:3 shouldDie:NO];
+}
+
+// Any live cell with more than three live neighbours dies, as if by overcrowding.
+- (void)testOvercrowding
+{
+    [self aliveCellWithNeighbours:4 shouldDie:YES];
+    [self aliveCellWithNeighbours:5 shouldDie:YES];
+    [self aliveCellWithNeighbours:6 shouldDie:YES];
+    [self aliveCellWithNeighbours:7 shouldDie:YES];
+    [self aliveCellWithNeighbours:8 shouldDie:YES];
+}
+
+// Any dead cell with exactly three live neighbours becomes a live cell, as if by reproduction.
+- (void)testReproduction
+{
+    [self deadCellWithNeighbours:3 shouldDie:NO];
+
+    [self deadCellWithNeighbours:2 shouldDie:YES];
+    [self deadCellWithNeighbours:4 shouldDie:YES];
+}
+
+- (void)testCanCreateWorld
+{
+    DLWorld *world = [[DLWorld alloc] init];
+
+    XCTAssertNotNil(world, @"there is world");
+}
+
+- (void)testWorldHasDeadCellsByDefault
+{
+    DLWorld *world = [[DLWorld alloc] init];
+
+    DLCell *cell = [world cellAtX:0 andY:0];
+
+    XCTAssertFalse(cell.alive, @"cell should be dead");
+}
+
+@end