Class SequenceSlice

java.lang.Object
net.sf.saxon.value.SequenceSlice
All Implemented Interfaces:
GroundedValue, Sequence

public class SequenceSlice extends 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 Details

    • SequenceSlice

      public SequenceSlice(List<? extends Item> value, int offset, int length)
      Construct an sequence from a slice of a list of items. Note, the list of items is used as is, which means the caller must not subsequently change its contents.
      Parameters:
      value - the list of items
      offset - the zero-based position of the first item to be included in the sequence
      length - the number of items to be included in the sequence; if this exceeds the number of items available for inclusion, include all items up to the end of the sequence
      Throws:
      IndexOutOfBoundsException - if offset < 0 or length < 0 or offset + length < value.size()
  • Method Details

    • getStringValue

      public 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 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:
    • 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
    • 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
    • asIterable

      public 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 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.