.. _functx_distinct-nodes:

=====================
functx:distinct-nodes
===================== 

The distinct XML nodes in a sequence (by node identity)

Description
~~~~~~~~~~~
The functx:distinct-nodes function returns the distinct nodes (based on node 
identity) in a sequence. It does this without resorting them in document order 
(it takes the first occurrence of each distinct node).It is different from the 
built-in fn:distinct-values function in that it returns nodes rather than atomic 
values, and it does not take into account the values (content) of the nodes, 
just their identity.

Note: if you want them to be resorted in document order, or you don't care, you 
can simply use the expression "$nodes/." (without the quotes), which works 
because the slash operator removes duplicates and resorts. The "." in the 
expression returns the node itself. 

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   * - **Parameters**
     - **Description**
   * - nodes:node()
     - the node sequence

Examples
~~~~~~~~
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   * - **XPath**
     - **Results**
     - **Explanation**
   * - functx:distinct-nodes(($in-xml/child, $in-xml/*))
     - <child>1</child> <child>2</child> <child>3</child> <child>3</child>
     - The two child elements that contain 3 have distinct identities, even if they contain the same content.
   * - functx:distinct-nodes(($in-xml/child[3], $in-xml/*))
     - <child>3</child> <child>1</child> <child>2</child> <child>3</child>
     - The 3  appears first because it is first in the input sequence.
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   :widths: 50 50
   :header-rows: 1

   * - **XPath**
     - **Results**
   * - functx:distinct-nodes(($in-xml/child, $in-xml/*))
     - <child>1</child> <child>2</child> <child>3</child> <child>3</child>
   * - functx:distinct-nodes(($in-xml/child[3], $in-xml/*))
     - <child>3</child> <child>1</child> <child>2</child> <child>3</child>

Depends On
~~~~~~~~~~
* :ref:`functx_is-node-in-sequence`.

See Also
~~~~~~~~

.. toctree::
   :titlesonly:
   :glob:

* :ref:`functx_distinct-deep`.
* :ref:`distinct-values`.