XdmValue

java.lang.Object
- net.sf.saxon.s9api.XdmValue

All Implemented Interfaces:

java.lang.Iterable<XdmItem>

Direct Known Subclasses:

XdmEmptySequence, XdmItem
```
public class XdmValue
extends java.lang.Object
implements java.lang.Iterable<XdmItem>
```
An value in the XDM data model. A value is a sequence of zero or more items, each item being either an atomic value or a node.
An XdmValue is immutable.

A sequence consisting of a single item may be represented as an instance of XdmItem, which is a subtype of XdmValue. However, there is no guarantee that a sequence of length one will always be an instance of XdmItem.

Similarly, a zero-length sequence may be represented as an instance of XdmEmptySequence, but there is no guarantee that every sequence of length zero will always be an instance of XdmEmptySequence.

Since:

9.0

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`XdmValue()`
	`XdmValue(java.lang.Iterable<? extends XdmItem> items)` Create an XdmValue as a sequence of XdmItem objects
	`XdmValue(java.util.Iterator<? extends XdmItem> iterator)` Create an XdmValue containing the items returned by an `Iterator`.
	`XdmValue(java.util.stream.Stream<? extends XdmItem> stream)` Create an XdmValue containing the results of reading a Stream

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`XdmValue`	`append(XdmValue otherValue)` Create a new XdmValue by concatenating the contents of this XdmValue and another XdmValue into a single sequence.
`XdmValue`	`documentOrder()` Return a new XdmValue containing the nodes present in this XdmValue, with duplicates eliminated, and sorted into document order
`protected static XdmValue`	`fromGroundedValue(GroundedValue<? extends Item> value)`
`GroundedValue<? extends Item>`	`getUnderlyingValue()` Get the underlying implementation object representing the value.
`XdmItem`	`itemAt(int n)` Get the n'th item in the value, counting from zero.
`java.util.Iterator<XdmItem>`	`iterator()` Get an iterator over the items in this value.
`static XdmValue`	`makeSequence(java.lang.Iterable list)` Make an XDM sequence from a Java `Iterable`.
`static XdmValue`	`makeValue(java.lang.Object o)` Make an XDM value from a Java object.
`<T extends XdmItem> XdmStream<T>`	`select(Step<T> step)` Get a stream of items by applying a `Step` to the items in this value.
`protected void`	`setValue(GroundedValue<? extends Item> value)`
`int`	`size()` Get the number of items in the sequence
`XdmStream<? extends XdmItem>`	`stream()` Get a stream comprising the items in this value
`java.lang.String`	`toString()` Create a string representation of the value.
`static XdmValue`	`wrap(AtomicSequence value)`
`static XdmValue`	`wrap(Sequence<? extends Item> value)` Create an XdmValue that wraps an existing Saxon Sequence

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.lang.Iterable
forEach, spliterator

- Constructor Detail
  - XdmValue
```
protected XdmValue()
```
  - XdmValue
```
public XdmValue(java.lang.Iterable<? extends XdmItem> items)
```
    Create an XdmValue as a sequence of XdmItem objects
    
    Parameters:
    
    items - a sequence of XdmItem objects. Note that if this is supplied as a list or similar collection, subsequent changes to the list/collection will have no effect on the XdmValue.
    
    Since:
    
    9.0.0.4
  - XdmValue
```
public XdmValue(java.util.Iterator<? extends XdmItem> iterator)
         throws SaxonApiException
```
    Create an XdmValue containing the items returned by an Iterator.
    
    Parameters:
    
    iterator - the iterator that supplies the values
    
    Throws:
    
    SaxonApiException - if an error occurs reading values from the supplied iterator
    
    Since:
    
    9.6. Extended in 9.9 to take any Iterator, not just an XdmSequenceIterator.
  - XdmValue
```
public XdmValue(java.util.stream.Stream<? extends XdmItem> stream)
         throws SaxonApiException
```
    Create an XdmValue containing the results of reading a Stream
    
    Parameters:
    
    stream - the stream to be read
    
    Throws:
    
    SaxonApiException
- Method Detail
  - fromGroundedValue
```
protected static XdmValue fromGroundedValue(GroundedValue<? extends Item> value)
```
  - setValue
```
protected void setValue(GroundedValue<? extends Item> value)
```
  - wrap
```
public static XdmValue wrap(Sequence<? extends Item> value)
```
    Create an XdmValue that wraps an existing Saxon Sequence
    Parameters:
    
    value - the supplied Sequence (which may be a singleton Item),
    
    Returns:
    an XdmValue corresponding to the supplied Sequence. If the supplied value is null, an empty sequence is returned. If the supplied value is an atomic value, the result will be an instance of XdmAtomicValue.
    
    If the supplied value is a node, the result will be an instance of XdmNode.
    
    If the supplied value is a map, the result will be an instance of XdmMap.
    
    If the supplied value is an array, the result will be an instance of XdmArray.
    
    If the supplied value is a function item, the result will be an instance of XdmFunctionItem.
    Throws:
    
    SaxonApiUncheckedException - if the supplied Sequence is not yet fully evaluated, and evaluation of the underlying expression fails with a dynamic error.
    
    Since:
    
    9.5 (previously a protected method)
  - wrap
```
public static XdmValue wrap(AtomicSequence value)
```
  - append
```
public XdmValue append(XdmValue otherValue)
```
    Create a new XdmValue by concatenating the contents of this XdmValue and another XdmValue into a single sequence. The two input XdmValue objects are unaffected by this operation.
    Note: creating a sequence of N values by successive calls on this method takes time proportional to N-squared.
    
    Parameters:
    
    otherValue - the value to be appended
    
    Returns:
    
    a new XdmValue containing the concatenation of the two input XdmValue objects
    
    Since:
    
    9.2
  - size
```
public int size()
```
    Get the number of items in the sequence
    
    Returns:
    
    the number of items in the value, considered as a sequence. Note that for arrays and maps, the answer will be 1 (one) since arrays and maps are items.
    
    Throws:
    
    SaxonApiUncheckedException - if the value is lazily evaluated and the delayed evaluation fails with a dynamic error.
  - itemAt
```
public XdmItem itemAt(int n)
               throws java.lang.IndexOutOfBoundsException,
                      SaxonApiUncheckedException
```
    Get the n'th item in the value, counting from zero.
    
    Parameters:
    
    n - the item that is required, counting the first item in the sequence as item zero
    
    Returns:
    
    the n'th item in the sequence making up the value, counting from zero
    
    Throws:
    
    java.lang.IndexOutOfBoundsException - if n is less than zero or greater than or equal to the number of items in the value
    
    SaxonApiUncheckedException - if the value is lazily evaluated and the delayed evaluation fails with a dynamic error.
  - iterator
```
public java.util.Iterator<XdmItem> iterator()
                                     throws SaxonApiUncheckedException
```
    Get an iterator over the items in this value.
    
    Specified by:
    
    iterator in interface java.lang.Iterable<XdmItem>
    
    Returns:
    
    an Iterator over the items in this value.
    
    Throws:
    
    SaxonApiUncheckedException - if the value is lazily evaluated and the delayed evaluation fails with a dynamic error.
  - getUnderlyingValue
```
public GroundedValue<? extends Item> getUnderlyingValue()
```
    Get the underlying implementation object representing the value. This method allows access to lower-level Saxon functionality, including classes and methods that offer no guarantee of stability across releases.
    
    Returns:
    
    the underlying implementation object representing the value
  - toString
```
public java.lang.String toString()
```
    Create a string representation of the value. The is the result of serializing the value using the adaptive serialization method.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    a string representation of the value
  - makeSequence
```
public static XdmValue makeSequence(java.lang.Iterable list)
                             throws java.lang.IllegalArgumentException
```
    Make an XDM sequence from a Java Iterable. Each value delivered by the iterable is first converted to an XDM value using the makeValue(Object) method; if the result is anything other than a single XDM item, it is then wrapped in an XdmArray.
    
    Returns:
    
    the result of the conversion if successful
    
    Throws:
    
    java.lang.IllegalArgumentException - if conversion is not possible
  - makeValue
```
public static XdmValue makeValue(java.lang.Object o)
                          throws java.lang.IllegalArgumentException
```
    Make an XDM value from a Java object. The supplied object may be any of the following:
    - An instance of XdmValue (for example, an XdmNode or XdmAtomicValue or XdmArray or XdmMap), which is returned unchanged
    - An instance of Sequence (for example, a NodeInfo or AtomicValue), which is wrapped as an XdmValue
    - An instance of Map, which is converted to an XDM Map using the XdmMap.makeMap(java.util.Map) method
    - A Java array, of any type, which is converted to an XDM Array using the XdmArray.makeArray(java.lang.Object[]) method
    - A Java collection, more specifically Iterable, which is converted to an XDM sequence using the makeSequence(Iterable) method
    - Any object that is convertible to an XDM atomic value using the method XdmAtomicValue.makeAtomicValue(Object)
    Returns:
    
    the result of the conversion if successful
    
    Throws:
    
    java.lang.IllegalArgumentException - if conversion is not possible
  - documentOrder
```
public XdmValue documentOrder()
                       throws SaxonApiException
```
    Return a new XdmValue containing the nodes present in this XdmValue, with duplicates eliminated, and sorted into document order
    
    Returns:
    
    the same nodes, sorted into document order, with duplicates eliminated
    
    Throws:
    
    SaxonApiException - if anything goes wrong (typically during delayed evaluation of the input sequence)
    
    java.lang.ClassCastException - if the sequence contains items that are not nodes
    
    Since:
    
    9.9
  - stream
```
public XdmStream<? extends XdmItem> stream()
```
    Get a stream comprising the items in this value
    
    Returns:
    
    a Stream over the items in this value
    
    Since:
    
    9.9
  - select
```
public <T extends XdmItem> XdmStream<T> select(Step<T> step)
```
    Get a stream of items by applying a Step to the items in this value. This operation is analogous to the Stream.flatMap operation in Java, or to the "!" operator in XPath.
    
    Parameters:
    
    step - the Step to be applied to the items in this value
    
    Returns:
    
    a Stream of items obtained by replacing each item X in this value by the items obtained by applying the Step function to X.
    
    Since:
    
    9.9

Class XdmValue

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Methods inherited from interface java.lang.Iterable

Constructor Detail

XdmValue

XdmValue

XdmValue

XdmValue

Method Detail

fromGroundedValue

setValue

wrap

wrap

append

size

itemAt

iterator

getUnderlyingValue

toString

makeSequence

makeValue

documentOrder

stream

select