Package net.sf.saxon.ma.zeno

Class ZenoSequence

java.lang.Object
net.sf.saxon.ma.zeno.ZenoSequence
All Implemented Interfaces:
GroundedValue, Sequence
public class ZenoSequence extends Object implements GroundedValue
An immutable XDM sequence implemented as a ZenoChain.

This sequence implementation

  • Constructor Details

    • ZenoSequence

      public ZenoSequence()
      Construct an empty ZenoSequence

    • ZenoSequence

      public ZenoSequence(ZenoChain<Item> chain)
      Constructor to create a ZenoSequence that wraps a supplied ZenoChain
      Parameters:
      chain - the supplied ZenoChain

  • Method Details

    • fromList

      public static ZenoSequence fromList(List<Item> items)
      Construct a ZenoSequence from a list of items
      Parameters:
      items - the items to be included
      Returns:
      the new ZenoSequence

    • iterate

      public SequenceIterator iterate()
      Get an iterator over the items in the sequence
      Specified by:
      iterate in interface GroundedValue
      Specified by:
      iterate in interface Sequence
      Returns:
      an iterator over the items in the sequence

    • itemAt

      public Item itemAt(int n)
      Get the item at a given position in the sequence
      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 item at the given position, or null if the position is out of range

    • 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, or null if the sequence is empty

    • 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 length 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 length of the sequence
      Specified by:
      getLength in interface GroundedValue
      Returns:
      the number of items in the sequence

    • getUnicodeStringValue

      public UnicodeString getUnicodeStringValue() throws XPathException
      Get a string representation of the sequence, consisting of the space-separated concatenation of the string representation of the items in the sequence
      Specified by:
      getUnicodeStringValue in interface GroundedValue
      Returns:
      a Unicode string containing the result of getting the string value of each item in the sequence, space-separated
      Throws:
      XPathException - if there is an item in the sequence with no string value, for example a map

    • getStringValue

      public String getStringValue() throws XPathException
      Get a string representation of the sequence, consisting of the space-separated concatenation of the string representation of the items in the sequence
      Specified by:
      getStringValue in interface GroundedValue
      Returns:
      a Unicode string containing the result of getting the string value of each item in the sequence, space-separated
      Throws:
      XPathException - if there is an item in the sequence with no string value, for example a map

    • append

      public ZenoSequence append(Item item)
      Append a single item to the end of the sequence
      Parameters:
      item - the item to be appended
      Returns:
      a new sequence containing the additional item. The original sequence is unchanged.

    • appendSequence

      public ZenoSequence appendSequence(GroundedValue items)
      Append a sequence of item to the end of the sequence
      Parameters:
      items - the items to be appended
      Returns:
      a new sequence containing the additional items. The original sequence is unchanged.

    • join

      public static ZenoSequence join(List<GroundedValue> segments)
      Create a ZenoSequence by concatenating a number of sequences
      Parameters:
      segments - the sequences to be concatenated
      Returns:
      the result of the concatenation