Class SortedIterator

    • Constructor Detail

      • SortedIterator

        protected SortedIterator()
      • SortedIterator

        public SortedIterator​(XPathContext context,
                              SequenceIterator base,
                              SortKeyEvaluator sortKeyEvaluator,
                              AtomicComparer[] comparators,
                              boolean createNewContext)
        Create a sorted iterator
        context - the dynamic XPath evaluation context
        base - an iterator over the sequence to be sorted
        sortKeyEvaluator - an object that allows the n'th sort key for a given item to be evaluated
        comparators - an array of AtomicComparers, one for each sort key, for comparing sort key values
        createNewContext - true if sort keys are computed relative to the item being sorted (as in XSLT but not XQuery)
    • Method Detail

      • setHostLanguage

        public void setHostLanguage​(HostLanguage language)
        Set the host language
        language - the host language (for example HostLanguage.XQUERY)
      • 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.

        This method must not be called unless the method supportsHasNext() returns true.

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

        public Item next()
        Get the next item, in sorted order
        Specified by:
        next in interface SequenceIterator
        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.
      • 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
        true if the 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
        the number of items in the sequence
      • buildArray

        protected void buildArray()
                           throws XPathException
        Create an array holding the items to be sorted and the values of their sort keys
        XPathException - if an error occurs for example in evaluating a sort key