Package net.sf.saxon.tree.iter

Class TwoItemIterator

java.lang.Object
net.sf.saxon.tree.iter.TwoItemIterator
All Implemented Interfaces:
Closeable, AutoCloseable, LastPositionFinder, SequenceIterator, GroundedIterator, LookaheadIterator
public class TwoItemIterator extends Object implements SequenceIterator, LookaheadIterator, GroundedIterator, LastPositionFinder
An iterator over a pair of objects (typically sub-expressions of an expression)

  • Constructor Details

    • TwoItemIterator

      public TwoItemIterator(Item one, Item two)
      Create an iterator over two objects
      Parameters:
      one - the first object to be returned
      two - the second object to be returned

  • Method Details

    • supportsHasNext

      public boolean supportsHasNext()
      Description copied from interface: LookaheadIterator
      Ask whether the hasNext() method can be called. This method must be called before calling hasNext(), because some iterators implement this interface, but only support look-ahead under particular circumstances (this is usually because they delegate to another iterator)
      Specified by:
      supportsHasNext in interface LookaheadIterator
      Returns:
      true if the LookaheadIterator.hasNext() method is available

    • hasNext

      public boolean hasNext()
      Returns true if the iteration has more elements. (In other words, returns true if next would return an element rather than throwing an exception.)
      Specified by:
      hasNext in interface LookaheadIterator
      Returns:
      true if the iterator has more elements.

    • next

      public Item next()
      Returns the next element in the iteration.
      Specified by:
      next in interface SequenceIterator
      Returns:
      the next element in the iteration, or null if there are no more

    • supportsGetLength

      public boolean supportsGetLength()
      Description copied from interface: LastPositionFinder
      Ask whether this iterator supports use of the LastPositionFinder.getLength() method. This method should always be called before calling LastPositionFinder.getLength(), because an iterator that implements this interface may support use of LastPositionFinder.getLength() in some situations and not in others
      Specified by:
      supportsGetLength in interface LastPositionFinder
      Returns:
      true if the LastPositionFinder.getLength() method can be called to determine the length of the underlying sequence.

    • getLength

      public int getLength()
      Description copied from interface: LastPositionFinder
      Get the last position (that is, the number of items in the sequence). This method is non-destructive: it does not change the state of the iterator. The result is undefined if the next() method of the iterator has already returned null. This method must not be called unless the LastPositionFinder.supportsGetLength() has been called and has returned true.
      Specified by:
      getLength in interface LastPositionFinder
      Returns:
      the number of items in the sequence

    • isActuallyGrounded

      public boolean isActuallyGrounded()
      Description copied from interface: GroundedIterator
      Ask if the iterator is actually grounded. This method must be called before calling GroundedIterator.materialize() or GroundedIterator.getResidue(), because the iterator might be grounded under some conditions and not others (usually when it delegates to another iterator)
      Specified by:
      isActuallyGrounded in interface GroundedIterator
      Returns:
      true if this iterator is grounded

    • getResidue

      public GroundedValue getResidue()
      Description copied from interface: GroundedIterator
      Return a GroundedValue containing all the remaining items in the sequence returned by this SequenceIterator, starting at the current position. This should be an "in-memory" value, not a Closure. This method does not change the state of the iterator (in particular, it does not consume the iterator).
      Specified by:
      getResidue in interface GroundedIterator
      Returns:
      the corresponding Value