RAC的retry数量计算

数量计算——retry：

// retry可以无限的重复、也可以设置重复的次数、即使遇到错误的信号依然执迷不悟的执行 且能直接忽视错误信号。
[[[[RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
  [subscriber sendNext:@"aaaa"];
  [subscriber sendNext:@"bbbb"];
  [subscriber sendNext:@"cccc"];
  [subscriber sendNext:@"dddd"];
  [subscriber sendCompleted];
  return [RACDisposable disposableWithBlock:^{
    NSLog(@"完成...");
  }];
}] retry] subscribeNext:^(id x) {
  NSLog(@"subscribeNext:%@",x);
}] dispose];

[[[[RACSignal createSignal:^RACDisposable *(id<RACSubscriber> subscriber) {
  [subscriber sendNext:@"aaaa"];
  [subscriber sendNext:@"bbbb"];
  [subscriber sendNext:@"cccc"];
  [subscriber sendNext:@"dddd"];
  [subscriber sendCompleted];
  return [RACDisposable disposableWithBlock:^{
    NSLog(@"完成...");
  }];
}] retry:2] subscribeNext:^(id x) {
  NSLog(@"subscribeNext:%@",x);
}] dispose];