SequenceExtent

java.lang.Object
- net.sf.saxon.value.SequenceExtent<T>

All Implemented Interfaces:

GroundedValue, Sequence
```
public class SequenceExtent<T extends Item>
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 Summary

Constructors
Constructor and Description
`SequenceExtent(List<? extends T> list)` Construct a SequenceExtent from a List.
`SequenceExtent(SequenceExtent<T> ext, int start, int length)` Construct a SequenceExtent as a view of another SequenceExtent
`SequenceExtent(SequenceIterator<T> iter)` Construct a sequence containing all the items in a SequenceIterator.
`SequenceExtent(T[] items)` Construct an sequence from an array of items.
`SequenceExtent(T[] value, int start, int length)` Construct a SequenceExtent from part of an array of items

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`effectiveBooleanValue()` Get the effective boolean value
`int`	`getCardinality()` Determine the cardinality
`ItemType`	`getItemType(TypeHierarchy th)` Get the (lowest common) item type
`int`	`getLength()` Get the number of items in the sequence
`String`	`getStringValue()` Get the string value of this sequence.
`CharSequence`	`getStringValueCS()` Get the string value of this sequence.
`Item`	`head()` Get the first item in the sequence.
`T`	`itemAt(int n)` Get the n'th item in the sequence (starting with 0 as the first item)
`ArrayIterator<T>`	`iterate()` Return an iterator over this sequence.
`static <T extends Item> Sequence`	`makeSequenceExtent(List<T> input)` Factory method to make a Value holding the contents of any List of items
`static <T extends Item> GroundedValue`	`makeSequenceExtent(SequenceIterator<T> iter)` Factory method to make a Value holding the contents of any SequenceIterator
`GroundedValue`	`reduce()` Reduce the sequence to its simplest form.
`UnfailingIterator<T>`	`reverseIterate()` Return an enumeration of this sequence in reverse order (used for reverse axes)
`GroundedValue`	`subsequence(int start, int length)` Get a subsequence of the value
`void`	`swap(int a, int b)` Swap two items (needed to support sorting)
`String`	`toString()`

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

- Constructor Detail
  - SequenceExtent
```
public SequenceExtent(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
  - SequenceExtent
```
public SequenceExtent(T[] value,
              int start,
              int length)
```
    Construct a SequenceExtent from part of an array of items
    
    Parameters:
    value - The array
    start - zero-based offset of the first item in the array that is to be included in the new SequenceExtent
    length - The number of items in the new SequenceExtent
  - SequenceExtent
```
public SequenceExtent(SequenceExtent<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
  - SequenceExtent
```
public SequenceExtent(List<? extends T> list)
```
    Construct a SequenceExtent from a List. The members of the list must all be Items
    
    Parameters:
    list - the list of items to be included in the sequence
  - SequenceExtent
```
public SequenceExtent(SequenceIterator<T> iter)
               throws XPathException
```
    Construct a sequence containing all the items in a SequenceIterator.
    
    Parameters:
    iter - The supplied sequence of items. This must be positioned at the start, so that hasNext() returns true if there are any nodes in the node-set, and next() returns the first node.
    
    Throws:
    
    XPathException - if reading the items using the SequenceIterator raises an error
- Method Detail
  - makeSequenceExtent
```
public static <T extends Item> GroundedValue makeSequenceExtent(SequenceIterator<T> iter)
                                        throws XPathException
```
    Factory method to make a Value holding the contents of any SequenceIterator
    
    Parameters:
    iter - a Sequence iterator that will be consumed to deliver the items in the sequence
    
    Returns:
    a ValueRepresentation holding the items delivered by the SequenceIterator. If the sequence is empty the result will be an instance of EmptySequence. If it is of length one, the result will be an Item. In all other cases, it will be an instance of SequenceExtent.
    
    Throws:
    
    XPathException - if an error occurs processing the values from the iterator.
  - makeSequenceExtent
```
public static <T extends Item> Sequence makeSequenceExtent(List<T> input)
```
    Factory method to make a Value holding the contents of any List of items
    
    Parameters:
    input - a List containing the items in the sequence
    
    Returns:
    a ValueRepresentation holding the items in the list. If the sequence is empty the result will be an instance of EmptySequence. If it is of length one, the result will be an Item. In all other cases, it will be an instance of SequenceExtent.
  - 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()
          throws XPathException
```
    Get the first item in the sequence.
    
    Specified by:
    
    head in interface Sequence
    
    Returns:
    the first item in the sequence if there is one, or null if the sequence is empty
    
    Throws:
    
    XPathException - in the situation where the sequence is evaluated lazily, and evaluation of the first item causes a dynamic error.
  - 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:
    Cardinality
  - getItemType
```
public ItemType getItemType(TypeHierarchy th)
```
    Get the (lowest common) item type
    
    Parameters:
    th - the type hierarchy cache. If null, the returned value may be less precise
    
    Returns:
    integer identifying an item type to which all the items in this sequence conform
  - itemAt
```
public T 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
  - swap
```
public void swap(int a,
        int b)
```
    Swap two items (needed to support sorting)
    
    Parameters:
    a - the position of the first item to be swapped
    b - the position of the second item to be swapped
  - iterate
```
public ArrayIterator<T> iterate()
```
    Return an iterator over this sequence.
    
    Specified by:
    
    iterate in interface Sequence
    
    Returns:
    the required SequenceIterator, positioned at the start of the sequence
  - reverseIterate
```
public UnfailingIterator<T> reverseIterate()
```
    Return an enumeration of this sequence in reverse order (used for reverse axes)
    
    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)
  - 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 SingletonItem. Otherwise, the result will typically be unchanged.
    
    Specified by:
    
    reduce in interface GroundedValue
    
    Returns:
    the simplified sequence

Class SequenceExtent<T extends Item>

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Constructor Detail

SequenceExtent

SequenceExtent

SequenceExtent

SequenceExtent

SequenceExtent

Method Detail

makeSequenceExtent

makeSequenceExtent

getStringValue

getStringValueCS

head

getLength

getCardinality

getItemType

itemAt

swap

iterate

reverseIterate

effectiveBooleanValue

subsequence

toString

reduce