Package net.sf.saxon.ma.zeno

Class ZenoSequence.ZenoSequenceIterator

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      int getLength()
      Get the last position (that is, the number of items in the sequence).
      GroundedValue getResidue()
      Return a GroundedValue containing all the remaining items in the sequence returned by this SequenceIterator, starting at the current position.
      boolean hasNext()
      Determine whether there are more items to come.
      boolean isActuallyGrounded()
      Ask if the iterator is actually grounded.
      GroundedValue materialize()
      Create a GroundedValue (a sequence materialized in memory) containing all the values delivered by this SequenceIterator.
      Item next()
      Get the next item in the sequence.
      boolean supportsGetLength()
      Ask whether this iterator supports use of the LastPositionFinder.getLength() method.
      boolean supportsHasNext()
      Ask whether the hasNext() method can be called.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • ZenoSequenceIterator

        public ZenoSequenceIterator​(ZenoSequence sequence)

    • Method Detail

      • next

        public Item next()
        Description copied from interface: SequenceIterator
        Get the next item in the sequence. This method changes the state of the iterator.
        Specified by:
        next in interface SequenceIterator
        Returns:
        the next item, or null if there are no more items. Once a call on next() has returned null, no further calls should be made. The preferred action for an iterator if subsequent calls on next() are made is to return null again, and all implementations within Saxon follow this rule.

      • 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

      • 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

      • materialize

        public GroundedValue materialize()
        Description copied from interface: GroundedIterator
        Create a GroundedValue (a sequence materialized in memory) containing all the values delivered by this SequenceIterator. The method must only be used when the SequenceIterator is positioned at the start. If it is not positioned at the start, then it is implementation-dependant whether the returned sequence contains all the nodes delivered by the SequenceIterator from the beginning, or only those delivered starting at the current position.

        It is implementation-dependant whether this method consumes the SequenceIterator. (More specifically, in the current implementation: if the iterator is backed by a GroundedValue, then that value is returned and the iterator is not consumed; otherwise, the iterator is consumed and the method returns the remaining items after the current position only).

        Specified by:
        materialize in interface GroundedIterator
        Returns:
        a sequence containing all the items delivered by this SequenceIterator.

      • 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()
        Description copied from interface: LookaheadIterator
        Determine whether there are more items to come. Note that this operation is stateless and it is not necessary (or usual) to call it before calling next(). It is used only when there is an explicit need to tell if we are at the last element.

        This method must not be called unless the result of LookaheadIterator.supportsHasNext() is true.

        Specified by:
        hasNext in interface LookaheadIterator
        Returns:
        true if there are more items in the sequence