gistfile1.m

#define DDFOREACH(_ARRAY_, _BLOCK_) { \
    [_ARRAY_ enumerateObjectsUsingBlock:^(id object, NSUInteger idx, BOOL *stop) { \
        _BLOCK_(object); \
    }]; \
}


#define ddbreak *stop = YES; return;

void doForeach(void)
{
    NSArray * colors = [NSArray arrayWithObjects:@"Red", @"Green", @"Blue", nil];
    DDFOREACH(colors, ^(NSString * color){
        NSLog(@"Color: %@", color);
        if ([color length] == 5)
            ddbreak;
        NSLog(@"Done");
    });
}