net.sf.saxon.ma.arrays

Class SimpleArrayItem

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.ma.arrays.SimpleArrayItem

All Implemented Interfaces:

Iterable<Sequence>, PullEvent, Callable, ArrayItem, Function, GroundedValue, Item, Sequence

public class SimpleArrayItem
extends AbstractItem
implements ArrayItem

A simple implementation of XDM array items, in which the array is backed by a Java List.

Field Summary

Fields

Modifier and Type	Field and Description
static SimpleArrayItem	EMPTY_ARRAY

Fields inherited from interface net.sf.saxon.ma.arrays.ArrayItem

SINGLE_ARRAY_TYPE

Constructor Summary

Constructors

Constructor and Description
SimpleArrayItem(List<Sequence> members)

Method Summary

Methods

Modifier and Type	Method and Description
AtomicSequence	atomize() Atomize the item.
Sequence	call(XPathContext context, Sequence[] args) Invoke the array in its role as a function
ArrayItem	concat(ArrayItem other) Concatenate this array with another
boolean	deepEquals(Function other, XPathContext context, AtomicComparer comparer, int flags) Test whether this array is deep-equal to another array, under the rules of the deep-equal function
boolean	effectiveBooleanValue() Get the effective boolean value of this sequence
void	export(ExpressionPresenter out) Output information about this function item to the diagnostic explain() output
Sequence	get(int index) Get a member of the array
int	getArity() Get the arity of the function
String	getDescription() Get a description of this function for use in error messages.
FunctionItemType	getFunctionItemType() Get the item type of the function item
StructuredQName	getFunctionName() Get the name of the function, or null if it is anonymous
List<Sequence>	getMembers() Get a list of the members of the array
SequenceType	getMemberType() Get the lowest common item type of the members of the array
OperandRole[]	getOperandRoles() Get the roles of the arguments, for the purposes of streaming
String	getStringValue() Get the value of the item as a string.
CharSequence	getStringValueCS() Get the value of the item as a CharSequence.
boolean	isArray() Ask whether this function item is an array
boolean	isEmpty() Ask whether the array is empty
boolean	isMap() Ask whether this function item is a map
Iterator<Sequence>	iterator() Get the list of all members of the array
static SimpleArrayItem	makeSimpleArrayItem(SequenceIterator input)
ArrayItem	remove(int index) Remove a member from the array
int	size() Get the size of the array
String	toString() Output a string representation of the array, suitable for diagnostics

Methods inherited from class net.sf.saxon.om.AbstractItem

getLength, head, itemAt, iterate, reduce, subsequence

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.sf.saxon.om.Function

iterate

Methods inherited from interface net.sf.saxon.om.Item

head

Methods inherited from interface net.sf.saxon.om.GroundedValue

getLength, head, itemAt, reduce, subsequence

Field Detail

EMPTY_ARRAY

public static final SimpleArrayItem EMPTY_ARRAY

Constructor Detail

SimpleArrayItem

public SimpleArrayItem(List<Sequence> members)

Method Detail

makeSimpleArrayItem

public static SimpleArrayItem makeSimpleArrayItem(SequenceIterator input)
                                           throws XPathException

Throws:

XPathException

getOperandRoles

public OperandRole[] getOperandRoles()

Get the roles of the arguments, for the purposes of streaming

Specified by:

getOperandRoles in interface Function

Returns:

an array of OperandRole objects, one for each argument

atomize

public AtomicSequence atomize()
                       throws XPathException

Atomize the item.

Specified by:

atomize in interface Item

Returns:

the result of atomization

Throws:

XPathException - if atomization is not allowed for this kind of item

isArray

public boolean isArray()

Ask whether this function item is an array

Specified by:

isArray in interface Function

Returns:

true (it is an array)

isMap

public boolean isMap()

Ask whether this function item is a map

Specified by:

isMap in interface Function

Returns:

false (it is not a map)

get

public Sequence get(int index)
             throws XPathException

Get a member of the array

Specified by:

get in interface ArrayItem

Parameters:

index - the position of the member to retrieve (zero-based)

Returns:

the value at the given position.

Throws:

XPathException - if the index is out of range

size

public int size()

Get the size of the array

Specified by:

size in interface ArrayItem

Returns:

the number of members in this array

isEmpty

public boolean isEmpty()

Ask whether the array is empty

Specified by:

isEmpty in interface ArrayItem

Returns:

true if and only if the size of the array is zero

iterator

public Iterator<Sequence> iterator()

Get the list of all members of the array

Specified by:

iterator in interface Iterable<Sequence>

Specified by:

iterator in interface ArrayItem

Returns:

an iterator over the members of the array

remove

public ArrayItem remove(int index)
                 throws XPathException

Remove a member from the array

Specified by:

remove in interface ArrayItem

Parameters:

index - the position of the member to be removed (zero-based)

Returns:

a new array in which the requested member has been removed

Throws:

XPathException - if the index is out of range

concat

public ArrayItem concat(ArrayItem other)

Concatenate this array with another

Specified by:

concat in interface ArrayItem

Parameters:

other - the second array

Returns:

the concatenation of the two arrays; that is, an array containing first the members of this array, and then the members of the other array

getMemberType

public SequenceType getMemberType()

Get the lowest common item type of the members of the array

Specified by:

getMemberType in interface ArrayItem

Returns:

the most specific type to which all the members belong.

getFunctionItemType

public FunctionItemType getFunctionItemType()

Get the item type of the function item

Specified by:

getFunctionItemType in interface Function

Returns:

the function item's type

getFunctionName

public StructuredQName getFunctionName()

Get the name of the function, or null if it is anonymous

Specified by:

getFunctionName in interface Function

Returns:

the function name, or null for an anonymous function (which this one is)

getDescription

public String getDescription()

Get a description of this function for use in error messages. For named functions, the description is the function name (as a lexical QName). For others, it might be, for example, "inline function", or "partially-applied ends-with function".

Specified by:

getDescription in interface Function

Returns:

a description of the function for use in error messages

getArity

public int getArity()

Get the arity of the function

Specified by:

getArity in interface Function

Returns:

the number of arguments in the function signature (in this case, 1 (one))

call

public Sequence call(XPathContext context,
            Sequence[] args)
              throws XPathException

Invoke the array in its role as a function

Specified by:

call in interface Callable

Specified by:

call in interface Function

Parameters:

context - the XPath dynamic evaluation context

args - the actual arguments to be supplied (a single integer)

Returns:

the result of invoking the function

Throws:

XPathException - if a dynamic error occurs within the function

deepEquals

public boolean deepEquals(Function other,
                 XPathContext context,
                 AtomicComparer comparer,
                 int flags)
                   throws XPathException

Test whether this array is deep-equal to another array, under the rules of the deep-equal function

Specified by:

deepEquals in interface Function

Parameters:

other - the other function item

context - the dynamic evaluation context

comparer - the object to perform the comparison

flags - options for how the comparison is performed

Returns:

true if the two array items are deep-equal; false if they are not deep equal or if the other item is not an array

Throws:

XPathException - if the comparison cannot be performed

effectiveBooleanValue

public boolean effectiveBooleanValue()
                              throws XPathException

Get the effective boolean value of this sequence

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)

getStringValue

public String getStringValue()

Get the value of the item as a string. For arrays, there is no string value, so an exception is thrown.

Specified by:

getStringValue in interface GroundedValue

Specified by:

getStringValue in interface Item

Returns:

the string value of the item

Throws:

UnsupportedOperationException - if the item is an array (an unchecked exception is used here to avoid introducing exception handling to a large number of paths where it is not needed)

Since:

8.4

See Also:

getStringValueCS()

getStringValueCS

public CharSequence getStringValueCS()

Get the value of the item as a CharSequence. For arrays, there is no string value, so an exception is thrown.

Specified by:

getStringValueCS in interface GroundedValue

Specified by:

getStringValueCS in interface Item

Returns:

the string value of the item

Throws:

UnsupportedOperationException - if the item is an array (an unchecked exception is used here to avoid introducing exception handling to a large number of paths where it is not needed)

Since:

8.4

See Also:

getStringValueCS()

export

public void export(ExpressionPresenter out)

Output information about this function item to the diagnostic explain() output

Specified by:

export in interface Function

getMembers

public List<Sequence> getMembers()

Get a list of the members of the array

Specified by:

getMembers in interface ArrayItem

Returns:

the list of members. Note that this returns the actual contained member array, and this is mutable. Changes to this array are permitted only if the caller knows what they are doing, for example during initial construction of an array that will not be presented to the user until construction has finished.

toString

public String toString()

Output a string representation of the array, suitable for diagnostics

Overrides:

toString in class Object