Package net.sf.saxon.expr

Class BigRangeIterator

java.lang.Object
net.sf.saxon.tree.iter.RangeIterator
net.sf.saxon.expr.BigRangeIterator
All Implemented Interfaces:
Closeable, AutoCloseable, LastPositionFinder, SequenceIterator, AtomicIterator, GroundedIterator, LookaheadIterator
public class BigRangeIterator extends RangeIterator implements AtomicIterator, LastPositionFinder, LookaheadIterator
An Iterator that produces numeric values in a monotonic ascending or descending sequence, where the integers may exceed the range of a Long

  • Constructor Details

    • BigRangeIterator

      public BigRangeIterator(BigInteger start, BigInteger step, BigInteger end) throws XPathException
      Create an iterator over a range of monotonically increasing integers
      Parameters:
      start - the first integer in the sequence
      step - the increment: negative for descending sequence
      end - the last integer in the sequence. Must be >= start if ascending, or <= if descending.
      Throws:
      XPathException - if the max sequence length is exceeded

  • Method Details

    • getResidue

      public GroundedValue getResidue()
      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
      Specified by:
      getResidue in class RangeIterator
      Returns:
      the corresponding Value
      Throws:
      UncheckedXPathException - in the cases of subclasses (such as the iterator over a MemoClosure) which cause evaluation of expressions while materializing the value.

    • getFirst

      public IntegerValue getFirst()
      Specified by:
      getFirst in class RangeIterator

    • getLast

      public IntegerValue getLast()
      Specified by:
      getLast in class RangeIterator

    • getMin

      public IntegerValue getMin()
      Specified by:
      getMin in class RangeIterator

    • getMax

      public IntegerValue getMax()
      Specified by:
      getMax in class RangeIterator

    • getStep

      public IntegerValue getStep()
      Get the increment between successive values. For a descending iterator this will be negative value.
      Specified by:
      getStep in class RangeIterator
      Returns:
      the increment between successive values

    • 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

    • next

      public IntegerValue next()
      Description copied from interface: AtomicIterator
      Get the next atomic value in the sequence.
      Specified by:
      next in interface AtomicIterator
      Specified by:
      next in interface SequenceIterator
      Returns:
      the next Item. If there are no more items, return null.

    • 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