Class ManualIterator

    • Constructor Summary

      Constructors 
      Constructor Description
      ManualIterator()
      Create an uninitialized ManualIterator: this is only usable after the context item, position, and size (if required) have been initialized using setter methods.
      ManualIterator​(Item value)
      Create a ManualIterator supplying the context item, and setting the value of both "position()" and "last()" implicitly to 1.
      ManualIterator​(Item value, int position)
      Create a ManualIterator initializing the context item and position.
    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      Item current()
      Get the current value in the sequence (the one returned by the most recent call on next()).
      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.
      ManualIterator getReverseIterator()
      Get a new SequenceIterator that returns the same items in reverse order.
      boolean hasNext()
      Determine whether there are more items to come.
      void incrementPosition()
      Advance the current position by one.
      boolean isActuallyGrounded()
      Ask if the iterator is actually grounded.
      GroundedValue materialize()
      Return a Value containing all the items in the sequence returned by this SequenceIterator
      Item next()
      Get the next item in the sequence.
      int position()
      Return the current position in the sequence.
      void setContextItem​(Item value)
      Set (or reset) the context item
      void setLengthFinder​(java.util.function.Supplier<java.lang.Integer> finder)
      Set a callback function that can be invoked to get the value of last()
      void setPosition​(int position)
      Set the current position to a specific value
      boolean supportsGetLength()
      Ask whether this iterator supports use of the getLength() method.
      boolean supportsHasNext()
      Ask whether the iterator supports lookahead.
      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
    • Constructor Detail

      • ManualIterator

        public ManualIterator()
        Create an uninitialized ManualIterator: this is only usable after the context item, position, and size (if required) have been initialized using setter methods.
      • ManualIterator

        public ManualIterator​(Item value,
                              int position)
        Create a ManualIterator initializing the context item and position. The value of "last()" for such an iterator is unknown unless a LastPositionFinder is supplied.
        Parameters:
        value - the context item. May be null if the value is to be initialized later.
        position - the context position
      • ManualIterator

        public ManualIterator​(Item value)
        Create a ManualIterator supplying the context item, and setting the value of both "position()" and "last()" implicitly to 1.
        Parameters:
        value - the context item
    • Method Detail

      • setContextItem

        public void setContextItem​(Item value)
        Set (or reset) the context item
        Parameters:
        value - the context item
      • setLengthFinder

        public void setLengthFinder​(java.util.function.Supplier<java.lang.Integer> finder)
        Set a callback function that can be invoked to get the value of last()
        Parameters:
        finder - the callback
      • incrementPosition

        public void incrementPosition()
        Advance the current position by one.
      • setPosition

        public void setPosition​(int position)
        Set the current position to a specific value
        Parameters:
        position - the new current position
      • supportsHasNext

        public boolean supportsHasNext()
        Ask whether the iterator supports lookahead.
        Specified by:
        supportsHasNext in interface LookaheadIterator
        Returns:
        true (calling hasNext() is allowed, returns true if the value of position() is less than the value of length())
      • 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
        Returns:
        true if there are more items
      • 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.
      • current

        public Item current()
        Description copied from interface: FocusIterator
        Get the current value in the sequence (the one returned by the most recent call on next()). This will be null before the first call of next(). This method does not change the state of the iterator.
        Specified by:
        current in interface FocusIterator
        Returns:
        the current item, the one most recently returned by a call on next(). Returns null if next() has not been called, or if the end of the sequence has been reached.
      • position

        public int position()
        Return the current position in the sequence.
        Specified by:
        position in interface FocusIterator
        Returns:
        0 before the first call on next(); 1 before the second call on next(); -1 after the second call on next().
      • supportsGetLength

        public boolean supportsGetLength()
        Ask whether this iterator supports use of the getLength() method. This method should always be called before calling getLength(), because an iterator that implements this interface may support use of getLength() in some situations and not in others
        Specified by:
        supportsGetLength in interface LastPositionFinder
        Returns:
        true if the getLength() method can be called to determine the length of the underlying sequence. This implementation always returns true (despite the fact that when streaming, a call to getLength() will actually fail)
      • getReverseIterator

        public ManualIterator getReverseIterator()
        Description copied from interface: ReversibleIterator
        Get a new SequenceIterator that returns the same items in reverse order. If this SequenceIterator is an AxisIterator, then the returned SequenceIterator must also be an AxisIterator.
        Specified by:
        getReverseIterator in interface ReversibleIterator
        Returns:
        an iterator over the items in reverse order
      • materialize

        public GroundedValue materialize()
        Return a Value containing all the items in the sequence returned by this SequenceIterator
        Specified by:
        materialize in interface GroundedIterator
        Returns:
        the corresponding Value. If the value is a closure or a function call package, it will be evaluated and expanded.
      • 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