Package org.aksw.commons.util.stream

Interface Streamer<V,T>

Type Parameters:
V - The type of the store from which to stream items
T - The item type to stream
Functional Interface:
This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.
@FunctionalInterface public interface Streamer<V,T>
A streamer returns a stream of items from a collection-like object (referred to as a 'store') given as the argument. For example, in the case of a map data structure a streamer may return any of its key, value or entry set. If the actual type of the collection is not known the {streamRaw(Object) method should be used.
Author:
Claus Stadler 11/09/2020

  • Method Summary

    Modifier and Type
    Method
    Description
    default <U> Streamer<V,U>
    mapItems(Function<T,U> itemTransform)
    Convenience method to derive a new streamer that transforms the items emitted by the original streamer.
    default <U> Streamer<V,U>
    mapStream(StreamFunction<T,U> streamTransform)
    Convenience method that yields a new Streamer that wraps this streamer such that its streams are transformed by the given streamTransform.
    Stream<T>
    stream(V store)
     
    default Stream<T>
    streamRaw(Object store)
    Delegate to stream(Object).

  • Method Details

    • stream

      Stream<T> stream(V store)

    • mapStream

      default <U> Streamer<V,U> mapStream(StreamFunction<T,U> streamTransform)
      Convenience method that yields a new Streamer that wraps this streamer such that its streams are transformed by the given streamTransform.
      Type Parameters:
      U -
      Parameters:
      streamTransform -
      Returns:

    • mapItems

      default <U> Streamer<V,U> mapItems(Function<T,U> itemTransform)
      Convenience method to derive a new streamer that transforms the items emitted by the original streamer.
      Type Parameters:
      U -
      Parameters:
      itemTransform -
      Returns:

    • streamRaw

      default Stream<T> streamRaw(Object store)
      Delegate to stream(Object).
      Parameters:
      store -
      Returns:
      A stream from given store. Arguments of incorrect type will cause a ClassCastException.