Class EmptyIterator

    • Constructor Detail

      • EmptyIterator

        protected EmptyIterator()
        Protected constructor
    • Method Detail

      • getInstance

        public static EmptyIterator getInstance()
        Get an EmptyIterator, an iterator over an empty sequence.
        an EmptyIterator (in practice, this always returns the same one)
      • next

        public Item next()
        Get the next item.
        Specified by:
        next in interface SequenceIterator
        the next item. For the EmptyIterator this is always null.
      • getLength

        public int getLength()
        Get the position of the last item in the sequence.
        Specified by:
        getLength in interface LastPositionFinder
        the position of the last item in the sequence, always zero in this implementation
      • getReverseIterator

        public EmptyIterator getReverseIterator()
        Get another iterator over the same items, in reverse order.
        Specified by:
        getReverseIterator in interface ReversibleIterator
        a reverse iterator over an empty sequence (in practice, it returns the same iterator each time)
      • materialize

        public GroundedValue materialize()
        Return a Value containing all the items in the sequence returned by this SequenceIterator. This should be an "in-memory" value, not a Closure.
        Specified by:
        materialize in interface GroundedIterator
        the corresponding Value
      • 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
        the corresponding Value
      • 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
        true if the LookaheadIterator.hasNext() method is available
      • hasNext

        public boolean hasNext()
        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.
        Specified by:
        hasNext in interface LookaheadIterator
        true if there are more nodes
      • ofNodes

        public static AxisIterator ofNodes()
        Static method to get an empty AxisIterator
        an empty AxisIterator
      • ofAtomic

        public static AtomicIterator ofAtomic()
        Static method to get an empty AtomicIterator
        an empty AtomicIterator