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코딩 코리아(Coding Korea): 스칼라의 TypeTag 위에 예제에서 볼수 있듯이 스칼라의 Manifest 는 Path dependent type 을 정확하게 확인할수 없는  결함을 갖고있다(스칼라에서 Path dependent type 은 같은 타입의 클라스라도 exact path 에 따라 instance 들이 틀리다고 명제되어있다. 그러므로 위의 경우에서도 둘다 Foo.Bar 이지만 path 가 틀리기 때문에 두 클라스의 Manifest 는 동일하지 않아야한다.) Manifest 처럼 TypeTag 의외도 ClassTypeTag 과 WeakTypeTag 이 있다. ClassTag 은 ClassManfiest 처럼 가장 위의 레벨에 있는 class type 만 생성한다. // ClassTag 은 Runtime 에서 오직 맨위에 레벨의 class type 만 제공하는것을 볼수있다 // 그러므로 Full type information 이 필요하면 TypeTag 을 써야한다 WeakTypeTag 은 주로 Macro 를 사용할때 같이 사용하게 된다. ...

Scala School - Advanced types implicit def strToInt(x: String) = x.toInt A view bound specifies a type that can be “viewed as” another. This makes sense for an operation that needs to “read” an object but doesn’t modify the object. Implicit functions allow automatic conversion they allow on-demand function application when this can help satisfy type inference This says that A has to be “viewable” as Int . , given our previous implicit, we can relax the constraint to viewa...

Singleton instance of akka actor per actor system | Anand's blog Akka does provide Cluster Singleton to create a singleton instance of an actor in a clustered environment. Akka extensions has two basic components namely Extensions and ExtensionId. Extensions are loaded only once per actor system. ExtensionId is needed to get the instance of our extension. Scala's Stackable Trait Pattern val queue = (new BasicIntQueue  | with Filtering with Incrementing) Scala with keyword usage - Stack Overflow ...

Streaming in Spark, Flink, and Kafka - DZone Big Data that every record will be processed exactly once, thereby eliminating any duplicates that might be available. Kafka Building real-time streaming data pipelines that reliably get data between systems or applications. Building real-time streaming applications that transform or react to the streams of data. the interchange of signals between cellphone towers financial transactions cars in motion emitting GPS signals ...

The DataCommand Posted from Diigo . The rest of my favorite links are here .

sql - PostgreSQL - query from bash script as database user 'postgres' - Stack Overflow Posted from Diigo . The rest of my favorite links are here .

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