net.sf.saxon.ma.arrays

Class SimpleArrayItem

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.ma.arrays.SimpleArrayItem

All Implemented Interfaces:

java.lang.Iterable<Sequence>, 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 Static constant value representing an empty array

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

SINGLE_ARRAY_TYPE

Constructor Summary

Constructors

Constructor and Description
SimpleArrayItem(java.util.List<Sequence> members) Construct an array whose members are arbitrary sequences

Method Summary

Modifier and Type	Method and Description
int	arrayLength() Get the size of the array
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
AnnotationList	getAnnotations() Get the function annotations (as defined in XQuery).
int	getArity() Get the arity of the function
java.lang.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
java.util.List<Sequence>	getMembers() Get a list of the members of the array
SequenceType	getMemberType(TypeHierarchy th) 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
java.lang.String	getStringValue() Get the value of the item as a string.
java.lang.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
boolean	isTrustedResultType() Check that result type is of the trusted system functions to return a result of the correct type
java.util.Iterator<Sequence>	iterator() Get the list of all members of the array
void	makeGrounded() Ensure that all the members are grounded.
XPathContext	makeNewContext(XPathContext callingContext) Prepare an XPathContext object for evaluating the function
static SimpleArrayItem	makeSimpleArrayItem(SequenceIterator input) Construct an array whose members are single items
ArrayItem	put(int index, Sequence newValue) Replace a member of the array
ArrayItem	remove(int pos) Remove a member from the array
ArrayItem	removeSeveral(IntSet positions) Remove zero or more members from the array
java.lang.String	toString() Output a string representation of the array, suitable for diagnostics

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

getLength, head, isStreamed, 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

Methods inherited from interface java.lang.Iterable

forEach, spliterator

Field Detail

EMPTY_ARRAY

public static final SimpleArrayItem EMPTY_ARRAY

Static constant value representing an empty array

Constructor Detail

SimpleArrayItem

public SimpleArrayItem(java.util.List<Sequence> members)

Construct an array whose members are arbitrary sequences

Parameters:

members - the list of values (in general, each value is a sequence) to form the members of the array

Method Detail

makeSimpleArrayItem

public static SimpleArrayItem makeSimpleArrayItem(SequenceIterator input)
                                           throws XPathException

Construct an array whose members are single items

Parameters:

input - an iterator over the items to make up the array

Returns:

an array in which each member is a single item, taken from the input sequence

Throws:

XPathException - if evaluating the SequenceIterator fails

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

makeGrounded

public void makeGrounded()
                  throws XPathException

Ensure that all the members are grounded. The idea is that a member may initially be a reference to a lazily-evaluated sequence, but once computed, the reference will be replaced with the actual value

Throws:

XPathException

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)

getAnnotations

public AnnotationList getAnnotations()

Get the function annotations (as defined in XQuery). Returns an empty list if there are no function annotations.

Specified by:

getAnnotations in interface Function

Returns:

the function annotations

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

put

public ArrayItem put(int index,
                     Sequence newValue)
              throws XPathException

Replace a member of the array

Specified by:

put in interface ArrayItem

Parameters:

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

newValue - the replacement value

Returns:

the value at the given position.

Throws:

XPathException - if the index is out of range

arrayLength

public int arrayLength()

Get the size of the array

Specified by:

arrayLength 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 java.util.Iterator<Sequence> iterator()

Get the list of all members of the array

Specified by:

iterator in interface java.lang.Iterable<Sequence>

Specified by:

iterator in interface ArrayItem

Returns:

an iterator over the members of the array

removeSeveral

public ArrayItem removeSeveral(IntSet positions)

Remove zero or more members from the array

Specified by:

removeSeveral in interface ArrayItem

Parameters:

positions - the positions of the members to be removed (zero-based). A value that is out of range is ignored.

Returns:

a new array in which the requested member has been removed

remove

public ArrayItem remove(int pos)

Remove a member from the array

Specified by:

remove in interface ArrayItem

Parameters:

pos - the position of the member to be removed (zero-based). A value that is out of range results in an IndexOutOfBoundsException

Returns:

a new array in which the requested member has been removed

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(TypeHierarchy th)

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 java.lang.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))

makeNewContext

public XPathContext makeNewContext(XPathContext callingContext)

Prepare an XPathContext object for evaluating the function

Specified by:

makeNewContext in interface Function

Parameters:

callingContext - the XPathContext of the function calling expression

Returns:

a suitable context for evaluating the function (which may or may not be the same as the caller's context)

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 java.lang.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:

java.lang.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 java.lang.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:

java.lang.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)
            throws XPathException

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

Specified by:

export in interface Function

Throws:

XPathException

isTrustedResultType

public boolean isTrustedResultType()

Description copied from interface: Function

Check that result type is of the trusted system functions to return a result of the correct type

Specified by:

isTrustedResultType in interface Function

getMembers

public java.util.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 java.lang.String toString()

Output a string representation of the array, suitable for diagnostics

Overrides:

toString in class java.lang.Object