langs a-z

Task/Collections/Objective-C/collections.m

@@ -0,0 +1,60 @@
+#import <Foundation/Foundation.h>
+
+void show_collection(id coll)
+{
+  id el;
+  NSEnumerator *en;
+  if ( [coll respondsToSelector: @selector(keyEnumerator)] ) {
+    en = [coll keyEnumerator];
+  } else {
+    en = [coll objectEnumerator];
+  }
+  while( (el = [en nextObject]) != nil)
+  {
+    if ( [coll respondsToSelector: @selector(countForObject:)] ) {
+      NSLog(@"%@ appears %d times", el, [coll countForObject: el]);
+    } else if ( [coll isKindOfClass: [NSDictionary class]] ) {
+      NSLog(@"%@ -> %@", el, [coll valueForKey: el]);
+    } else {
+      NSLog(@"%@", el);
+    }
+  }
+  printf("\n");
+}
+
+int main()
+{
+  NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
+
+  // create an empty set
+  NSMutableSet *set = [[NSMutableSet alloc] init];
+  // populate it
+  [set addObject: @"one"];
+  [set addObject: [NSNumber numberWithInt: 10]];
+  [set addObjectsFromArray: [NSArray arrayWithObjects: @"one",
+				     [NSNumber numberWithInt: 20],
+				     [NSNumber numberWithInt: 10],
+				     @"two", nil] ];
+  // let's show it
+  show_collection(set);
+
+  // create an empty counted set (a bag)
+  NSCountedSet *cset = [[NSCountedSet alloc] init];
+  // populate it
+  [cset addObject: @"one"];
+  [cset addObject: @"one"];
+  [cset addObject: @"two"];
+  // show it
+  show_collection(cset);
+
+  // create a dictionary
+  NSMutableDictionary *dict = [[NSMutableDictionary alloc] init];
+  // populate it
+  [dict setValue: [NSNumber numberWithInt: 4] forKey: @"four"];
+  [dict setValue: [NSNumber numberWithInt: 8] forKey: @"eight"];
+  // show it
+  show_collection(dict);
+
+  [pool release];
+  return EXIT_SUCCESS;
+}