tasks a-s

Task/Polymorphism/Objective-C/polymorphism.m

@@ -0,0 +1,73 @@
+#import <Foundation/Foundation.h>
+
+@interface RCPoint : NSObject {
+  int x, y;
+}
+-(id)initWithX:(int)x0;
+-(id)initWithX:(int)x0 andY:(int)y0;
+-(id)initWithPoint:(RCPoint *)p;
+@property (nonatomic) int x;
+@property (nonatomic) int y;
+@end
+
+@implementation RCPoint
+@synthesize x, y;
+-(id)initWithX:(int)x0 { return [self initWithX:x0 andY:0]; }
+-(id)initWithX:(int)x0 andY:(int)y0 {
+  if ((self = [super init])) {
+    x = x0;
+    y = y0;
+  }
+  return self;
+}
+-(id)initWithPoint:(RCPoint *)p { return [self initWithX:p.x andY:p.y]; }
+-(NSString *)description { return [NSString stringWithFormat:@"<RCPoint %p x: %d y: %d>", self, x, y]; }
+@end
+
+@interface RCCircle : RCPoint {
+  int r;
+}
+-(id)initWithCenter:(RCPoint *)p andRadius:(int)r0;
+-(id)initWithX:(int)x0 andY:(int)y0 andRadius:(int)r0;
+-(id)initWithCircle:(RCCircle *)c;
+@property (nonatomic) int r;
+@end
+
+@implementation RCCircle
+@synthesize r;
+-(id)initWithCenter:(RCPoint *)p andRadius:(int)r0 {
+  if ((self = [super initWithPoint:p])) {
+    r = r0;
+  }
+  return self;
+}
+-(id)initWithX:(int)x0 andY:(int)y0 andRadius:(int)r0 {
+  if ((self = [super initWithX:x0 andY:y0])) {
+    r = r0;
+  }
+  return self;
+}
+-(id)initWithCircle:(RCCircle *)c { return [self initWithX:c.x andY:c.y andRadius:c.r]; }
+-(NSString *)description { return [NSString stringWithFormat:@"<RCCircle %p x: %d y: %d r: %d>", self, x, y, r]; }
+@end
+
+int main(int argc, const char *argv[]) {
+  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+
+  NSLog(@"%@", [[[RCPoint alloc] init] autorelease]);
+  NSLog(@"%@", [[[RCPoint alloc] initWithX:3] autorelease]);
+  NSLog(@"%@", [[[RCPoint alloc] initWithX:3 andY:4] autorelease]);
+  NSLog(@"%@", [[[RCCircle alloc] init] autorelease]);
+  NSLog(@"%@", [[[RCCircle alloc] initWithX:3] autorelease]);
+  NSLog(@"%@", [[[RCCircle alloc] initWithX:3 andY:4] autorelease]);
+  NSLog(@"%@", [[[RCCircle alloc] initWithX:3 andY:4 andRadius:7] autorelease]);
+  RCPoint *p = [[[RCPoint alloc] initWithX:1 andY:2] autorelease];
+  NSLog(@"%@", [[[RCCircle alloc] initWithPoint:p] autorelease]);
+  NSLog(@"%@", [[[RCCircle alloc] initWithCenter:p andRadius:7] autorelease]);
+  NSLog(@"%d", p.x); // 1
+  p.x = 8;
+  NSLog(@"%d", p.x); // 8
+
+  [pool release];
+  return 0;
+}