net.sf.saxon.ma.arrays

Class AbstractArrayItem

java.lang.Object

net.sf.saxon.ma.arrays.ArrayItem

net.sf.saxon.ma.arrays.AbstractArrayItem

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

Direct Known Subclasses:

DelegatingArrayItem, ImmutableArrayItem, SimpleArrayItem

public abstract class AbstractArrayItem
extends ArrayItem

An abstract implementation of XDM array items, containing methods that can be implemented generically.

Constructor Summary

Constructors

Constructor and Description
AbstractArrayItem()

Method Summary

Modifier and Type	Method and Description
AtomicSequence	atomize() Atomize the item.
GroundedValue	call(XPathContext context, Sequence[] args) Invoke the array in its role as a function
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
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
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
UnicodeString	getUnicodeStringValue() Get the value of the item as a string.
boolean	isTrustedResultType() Ask if the function can be trusted to return a result of the correct type
XPathContext	makeNewContext(XPathContext callingContext, ContextOriginator originator) Prepare an XPathContext object for evaluating the function
java.lang.String	toString() Output a string representation of the array, suitable for diagnostics

Methods inherited from class net.sf.saxon.ma.arrays.ArrayItem

arrayLength, concat, get, getGenre, insert, isArray, isEmpty, isMap, members, put, remove, removeSeveral, subArray, toShortString

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

isSequenceVariadic

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

getLength, getStringValue, head, isStreamed, itemAt, iterate, reduce, subsequence

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

asIterable, concatenate, containsNode, materialize

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

makeRepeatable

Constructor Detail

AbstractArrayItem

public AbstractArrayItem()

Method Detail

getOperandRoles

public OperandRole[] getOperandRoles()

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

Returns:

an array of OperandRole objects, one for each argument

atomize

public AtomicSequence atomize()
                       throws XPathException

Atomize the item.

Returns:

the result of atomization

Throws:

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

getAnnotations

public AnnotationList getAnnotations()

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

Returns:

the function annotations

getFunctionItemType

public FunctionItemType getFunctionItemType()

Get the item type of the function item

Returns:

the function item's type

getFunctionName

public StructuredQName getFunctionName()

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

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".

Returns:

a description of the function for use in error messages

getArity

public int getArity()

Get the arity of the function

Returns:

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

makeNewContext

public XPathContext makeNewContext(XPathContext callingContext,
                                   ContextOriginator originator)

Prepare an XPathContext object for evaluating the function

Parameters:

callingContext - the XPathContext of the function calling expression

originator -

Returns:

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

call

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

Invoke the array in its role as a 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

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

Returns:

the effective boolean value

Throws:

XPathException - if the sequence has no effective boolean value (for example a sequence of two integers)

getUnicodeStringValue

public UnicodeString getUnicodeStringValue()

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

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

export

public void export(ExpressionPresenter out)
            throws XPathException

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

Parameters:

out - the destination for the information

Throws:

XPathException - if things go wrong

isTrustedResultType

public boolean isTrustedResultType()

Description copied from interface: Function

Ask if the function can be trusted to return a result of the correct type

Returns:

true if the implementation can be trusted

toString

public java.lang.String toString()

Output a string representation of the array, suitable for diagnostics

Overrides:

toString in class java.lang.Object

getMemberType

public SequenceType getMemberType(TypeHierarchy th)

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

Specified by:

getMemberType in class ArrayItem

Returns:

the most specific type to which all the members belong.