Package net.sf.saxon.value

Class SequenceExtent.Of<T extends Item>

java.lang.Object
net.sf.saxon.value.SequenceExtent
net.sf.saxon.value.SequenceExtent.Of<T>
All Implemented Interfaces:
Iterable<T>, GroundedValue, Sequence
Enclosing class:
SequenceExtent
public static class SequenceExtent.Of<T extends Item> extends SequenceExtent implements Iterable<T>

  • Constructor Details

    • Of

      public Of(List<T> list)
      Construct a SequenceExtent from a List. The members of the list must all be Items. The caller warrants that the list is effectively immutable.
      Parameters:
      list - the list of items to be included in the sequence

    • Of

      public Of(T[] 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

    • Of

      public Of(SequenceExtent.Of<T> ext, int start, int length)
      Construct a SequenceExtent as a view of another SequenceExtent
      Parameters:
      ext - The existing SequenceExtent
      start - zero-based offset of the first item in the existing SequenceExtent that is to be included in the new SequenceExtent
      length - The number of items in the new SequenceExtent

  • Method Details

    • iterate

      public ListIterator.Of<T> 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 SequenceIterator reverseIterate()
      Return an enumeration of this sequence in reverse order (used for reverse axes)
      Specified by:
      reverseIterate in class SequenceExtent
      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)

    • itemAt

      public Item itemAt(int n)
      Get the n'th item in the value, counting from zero (0)
      Specified by:
      itemAt in interface GroundedValue
      Parameters:
      n - the index of the required item, with zero (0) representing the first item in the sequence
      Returns:
      the n'th item if it exists, or null if the requested position is out of range

    • head

      public Item 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

    • getLength

      public int getLength()
      Description copied from interface: GroundedValue
      Get the size of the value (the number of items in the value, considered as a sequence)
      Specified by:
      getLength in interface GroundedValue
      Returns:
      the number of items in the sequence. Note that for a single item, including a map or array, the result is always 1 (one).

    • getUnicodeStringValue

      public UnicodeString getUnicodeStringValue() throws XPathException
      Description copied from interface: GroundedValue
      Get the string value of this sequence, as an instance of UnicodeString. The string value of an item is the result of applying the XPath 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

      The result of this method is always equivalent to the result of the GroundedValue.getStringValue() method. Use this method in preference either (a) if you need to use the value in a context where a UnicodeString is required, or (b) if the underlying value is held as a UnicodeString, or in a form that is readily converted to a UnicodeString. This is typically the case (i) when the value is a text or element node in a TinyTree, and (ii) when the value is a StringItem: that is, an atomic value of type xs:string.

      Specified by:
      getUnicodeStringValue 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)

    • getStringValue

      public String getStringValue() throws XPathException
      Description copied from interface: GroundedValue
      Get the string value of this sequence, as an instance of String. The string value of an item is the result of applying the XPath 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.

      The result of this method is always equivalent to the result of the GroundedValue.getUnicodeStringValue() method. Use this method in preference either (a) if you need to use the value in a context where a String is required, or (b) if the underlying value is held as a String, or in a form that is readily converted to a String. This is typically the case (i) when the value is an attribute node in a TinyTree, or (ii) any kind of node in a third-party tree model such as DOM.

      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)

    • 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 String toString()
      Overrides:
      toString in class 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

    • iterator

      public Iterator<T> iterator()
      Get an iterator (a Java Iterator) over the items in this sequence.
      Specified by:
      iterator in interface Iterable<T extends Item>
      Returns:
      an iterator over the items in this sequence.