Package net.sf.saxon.value

Class SequenceExtent

  • All Implemented Interfaces:
    GroundedValue, Sequence
    Direct Known Subclasses:
    OneOrMore
    public class SequenceExtent
extends java.lang.Object
implements GroundedValue
    A sequence value implemented extensionally. That is, this class represents a sequence by allocating memory to each item in the sequence.

    • Constructor Detail

      • SequenceExtent

        public SequenceExtent​(Item[] items)
        Construct an sequence from an array of items. Note, the array of items is used as is, which means the caller must not subsequently change its contents.
        Parameters:
        items - the array of items to be included in the sequence

      • SequenceExtent

        public SequenceExtent​(java.util.List<? extends Item> list)
        Construct a SequenceExtent from a List. The members of the list must all be Items
        Parameters:
        list - the list of items to be included in the sequence

      • SequenceExtent

        public SequenceExtent​(SequenceIterator iter)
               throws XPathException
        Construct a sequence containing all the remaining items in a SequenceIterator.
        Parameters:
        iter - The supplied sequence of items. The returned sequence will contain all items delivered by repeated calls on next() on this iterator, and the iterator will be consumed by calling the method.
        Throws:
        XPathException - if reading the items using the SequenceIterator raises an error

    • Method Detail

      • makeSequenceExtent

        public static GroundedValue makeSequenceExtent​(SequenceIterator iter)
                                        throws XPathException
        Deprecated.
        since 9.9: use SequenceIterator.materialize()
        Factory method to make a GroundedValue holding the contents of any SequenceIterator.
        Parameters:
        iter - a Sequence iterator that may or may not be consumed to deliver the items in the sequence. The iterator must be positioned at the start.
        Returns:
        a GroundedValue holding the items delivered by the SequenceIterator. If the sequence is empty the result will be an instance of EmptySequence. If it is of length one, the result will be an Item. In all other cases, it will be an instance of SequenceExtent.
        Throws:
        XPathException - if an error occurs processing the values from the iterator.

      • fromIterator

        public static GroundedValue fromIterator​(SequenceIterator iter)
                                  throws XPathException
        Deprecated.
        since 9.9: use SequenceIterator.materialize()
        Factory method to make a GroundedValue holding the contents of any SequenceIterator.
        Parameters:
        iter - a Sequence iterator that may or may not be consumed to deliver the items in the sequence. The iterator must be positioned at the start.
        Returns:
        a GroundedValue holding the items delivered by the SequenceIterator. If the sequence is empty the result will be an instance of EmptySequence. If it is of length one, the result will be an Item. In other cases, the actual implementation class is not defined.

        This method is intended primarily for internal use. For external applications, calling SequenceIterator.materialize() is preferable, because it recognizes cases that can be optimized (notably, cases where the iterator is already backed by an array or list in memory).

        Throws:
        XPathException - if an error occurs processing the values from the iterator.

      • makeResidue

        public static GroundedValue makeResidue​(SequenceIterator iter)
                                 throws XPathException
        Factory method to make a GroundedValue holding the remaining contents of any SequenceIterator, that is, the contents that have not yet been read
        Parameters:
        iter - a Sequence iterator that may or may not be consumed to deliver the items in the sequence. The iterator need not be positioned at the start.
        Returns:
        a GroundedValue holding the items delivered by the SequenceIterator. If the sequence is empty the result will be an instance of EmptySequence. If it is of length one, the result will be an Item. In all other cases, it will be an instance of SequenceExtent.
        Throws:
        XPathException - if an error occurs processing the values from the iterator.

      • makeSequenceExtent

        public static <T extends Item> GroundedValue makeSequenceExtent​(java.util.List<T> input)
        Factory method to make a Value holding the contents of any List of items
        Parameters:
        input - a List containing the items in the sequence. The caller guarantees that this list will not be subsequently modified.
        Returns:
        a ValueRepresentation holding the items in the list. If the sequence is empty the result will be an instance of EmptySequence. If it is of length one, the result will be an Item. In all other cases, it will be an instance of SequenceExtent.

      • getStringValue

        public java.lang.String getStringValue()
                                throws XPathException
        Description copied from interface: GroundedValue
        Get the string value of this sequence. The string value of an item is the result of applying the string() function. The string value of a sequence is the space-separated result of applying the string-join() function using a single space as the separator
        Specified by:
        getStringValue in interface GroundedValue
        Returns:
        the string value of the sequence.
        Throws:
        XPathException - if the sequence contains items that have no string value (for example, function items)

      • getStringValueCS

        public java.lang.CharSequence getStringValueCS()
                                        throws XPathException
        Description copied from interface: GroundedValue
        Get the string value of this sequence. The string value of an item is the result of applying the string() function. The string value of a sequence is the space-separated result of applying the string-join() function using a single space as the separator
        Specified by:
        getStringValueCS in interface GroundedValue
        Returns:
        the string value of the sequence.
        Throws:
        XPathException - if the sequence contains items that have no string value (for example, function items)

      • head

        public Item head()
        Get the first item in the sequence.
        Specified by:
        head in interface GroundedValue
        Specified by:
        head in interface Sequence
        Returns:
        the first item in the sequence if there is one, or null if the sequence is empty

      • getLength

        public int getLength()
        Get the number of items in the sequence
        Specified by:
        getLength in interface GroundedValue
        Returns:
        the number of items in the sequence

      • getCardinality

        public int getCardinality()
        Determine the cardinality
        Returns:
        the cardinality of the sequence, using the constants defined in net.sf.saxon.value.Cardinality
        See Also:
        Cardinality

      • itemAt

        public Item itemAt​(int n)
        Get the n'th item in the sequence (starting with 0 as the first item)
        Specified by:
        itemAt in interface GroundedValue
        Parameters:
        n - the position of the required item
        Returns:
        the n'th item in the sequence, or null if the position is out of range

      • iterate

        public ListIterator<? extends Item> iterate()
        Return an iterator over this sequence.
        Specified by:
        iterate in interface GroundedValue
        Specified by:
        iterate in interface Sequence
        Returns:
        the required SequenceIterator, positioned at the start of the sequence

      • reverseIterate

        public UnfailingIterator reverseIterate()
        Return an enumeration of this sequence in reverse order (used for reverse axes)
        Returns:
        an AxisIterator that processes the items in reverse order

      • effectiveBooleanValue

        public boolean effectiveBooleanValue()
                              throws XPathException
        Get the effective boolean value
        Specified by:
        effectiveBooleanValue in interface GroundedValue
        Returns:
        the effective boolean value
        Throws:
        XPathException - if the sequence has no effective boolean value (for example a sequence of two integers)

      • subsequence

        public GroundedValue subsequence​(int start,
                                 int length)
        Get a subsequence of the value
        Specified by:
        subsequence in interface GroundedValue
        Parameters:
        start - the index of the first item to be included in the result, counting from zero. A negative value is taken as zero. If the value is beyond the end of the sequence, an empty sequence is returned
        length - the number of items to be included in the result. Specify Integer.MAX_VALUE to get the subsequence up to the end of the base sequence. If the value is negative, an empty sequence is returned. If the value goes off the end of the sequence, the result returns items up to the end of the sequence
        Returns:
        the required subsequence. If min is

      • toString

        public java.lang.String toString()
        Overrides:
        toString in class java.lang.Object

      • reduce

        public GroundedValue reduce()
        Reduce the sequence to its simplest form. If the value is an empty sequence, the result will be EmptySequence.getInstance(). If the value is a single atomic value, the result will be an instance of AtomicValue. If the value is a single item of any other kind, the result will be an instance of One. Otherwise, the result will typically be unchanged.
        Specified by:
        reduce in interface GroundedValue
        Returns:
        the simplified sequence

      • asIterable

        public java.lang.Iterable<? extends Item> asIterable()
        Get the contents of this value in the form of a Java Iterable, so that it can be used in a for-each expression
        Specified by:
        asIterable in interface GroundedValue
        Returns:
        an Iterable containing the same sequence of items

      • iterator

        public java.util.Iterator<? extends Item> iterator()
        Get an iterator (a Java Iterator) over the items in this sequence.
        Returns:
        an iterator over the items in this sequence.