Package net.sf.saxon.om

Class ZeroOrMore<T extends Item>

  • All Implemented Interfaces:
    java.lang.Iterable<T>, GroundedValue, Sequence
    public class ZeroOrMore<T extends Item>
extends java.lang.Object
implements GroundedValue, java.lang.Iterable<T>
    A value that is a sequence containing one or more items. The main use is in declarations of reflexive extension functions, where declaring an argument of type <ZeroOrMore<IntegerValue>> triggers automatic type checking in the same way as for a native XSLT/XQuery function declaring the type as xs:integer*.

    • Constructor Detail

      • ZeroOrMore

        public ZeroOrMore​(T[] content)
        Create a sequence containing zero or one items
        Parameters:
        content - The content of the sequence

      • ZeroOrMore

        public ZeroOrMore​(java.util.List<T> content)

    • Method Detail

      • head

        public T head()
        Description copied from interface: GroundedValue
        Get the first item of the sequence. This differs from the parent interface in not allowing an exception
        Specified by:
        head in interface GroundedValue
        Specified by:
        head in interface Sequence
        Returns:
        the first item of the sequence, or null if the sequence is empty

      • iterate

        public ListIterator<T> iterate()
        Description copied from interface: GroundedValue
        Get an iterator over all the items in the sequence. This differs from the superclass method in not allowing an exception, either during this method call, or in the subsequent processing of the returned iterator.
        Specified by:
        iterate in interface GroundedValue
        Specified by:
        iterate in interface Sequence
        Returns:
        an iterator (meaning a Saxon SequenceIterator rather than a Java Iterator) over all the items in this Sequence.

      • iterator

        public java.util.Iterator<T> iterator()
        Specified by:
        iterator in interface java.lang.Iterable<T extends Item>

      • itemAt

        public T itemAt​(int n)
        Get the n'th item in the value, counting from 0
        Specified by:
        itemAt in interface GroundedValue
        Parameters:
        n - the index of the required item, with 0 representing the first item in the sequence
        Returns:
        the n'th item if it exists, or null otherwise

      • subsequence

        public ZeroOrMore<T> 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.

      • getLength

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

      • effectiveBooleanValue

        public boolean effectiveBooleanValue()
                              throws XPathException
        Get the effective boolean value of this sequence
        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)

      • getStringValue

        public java.lang.String getStringValue()
                                throws XPathException
        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
        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)

      • 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