Package org.eclipse.rdf4j.common.iteration

Class MinusIteration<E,X extends Exception>

java.lang.Object
org.eclipse.rdf4j.common.iteration.AbstractCloseableIteration<E,X>
org.eclipse.rdf4j.common.iteration.IterationWrapper<E,X>
org.eclipse.rdf4j.common.iteration.FilterIteration<E,X>
org.eclipse.rdf4j.common.iteration.MinusIteration<E,X>
All Implemented Interfaces:
AutoCloseable, CloseableIteration<E,X>, Iteration<E,X>
public class MinusIteration<E,X extends Exception> extends FilterIteration<E,X>
An Iteration that returns the results of an Iteration (the left argument) minus the results of another Iteration (the right argument). Optionally, the Iteration can be configured to filter duplicates from the returned elements.

Note that duplicates can also be filtered by wrapping this Iteration in a DistinctIteration, but that has a bit more overhead as it adds a second hash table lookup.

  • Constructor Details

    • MinusIteration

      public MinusIteration(Iteration<? extends E,X> leftArg, Iteration<? extends E,X> rightArg)
      Creates a new MinusIteration that returns the results of the left argument minus the results of the right argument. By default, duplicates are not filtered from the results.
      Parameters:
      leftArg - An Iteration containing the main set of elements.
      rightArg - An Iteration containing the set of elements that should be filtered from the main set.

    • MinusIteration

      public MinusIteration(Iteration<? extends E,X> leftArg, Iteration<? extends E,X> rightArg, boolean distinct)
      Creates a new MinusIteration that returns the results of the left argument minus the results of the right argument.
      Parameters:
      leftArg - An Iteration containing the main set of elements.
      rightArg - An Iteration containing the set of elements that should be filtered from the main set.
      distinct - Flag indicating whether duplicate elements should be filtered from the result.

    • MinusIteration

      public MinusIteration(Iteration<? extends E,X> leftArg, Iteration<? extends E,X> rightArg, boolean distinct, Supplier<Set<E>> setMaker)
      Creates a new MinusIteration that returns the results of the left argument minus the results of the right argument.
      Parameters:
      leftArg - An Iteration containing the main set of elements.
      rightArg - An Iteration containing the set of elements that should be filtered from the main set.
      distinct - Flag indicating whether duplicate elements should be filtered from the result.

  • Method Details

    • accept

      protected boolean accept(E object) throws X
      Description copied from class: FilterIteration
      Tests whether or not the specified object should be returned by this Iteration. All objects from the wrapped Iteration pass through this method in the same order as they are coming from the wrapped Iteration.
      Specified by:
      accept in class FilterIteration<E,X extends Exception>
      Parameters:
      object - The object to be tested.
      Returns:
      true if the object should be returned, false otherwise.
      Throws:
      X

    • handleClose

      protected void handleClose() throws X
      Description copied from class: IterationWrapper
      Closes this Iteration and also closes the wrapped Iteration if it is a CloseableIteration.
      Overrides:
      handleClose in class FilterIteration<E,X extends Exception>
      Throws:
      X