net.sf.saxon.functions

Class AbstractFunction

java.lang.Object

net.sf.saxon.functions.AbstractFunction

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

Direct Known Subclasses:

AtomicConstructorFunction, CallableFunction, CoercedFunction, CurriedFunction, ListConstructorFunction, OriginalFunction, SystemFunction, SystemFunctionWithBoundContextItem, UnionConstructorFunction, UnresolvedXQueryFunctionItem, UserFunctionReference.BoundUserFunction

public abstract class AbstractFunction
extends java.lang.Object
implements Function

Abstract superclass (and factory class) for implementations of Function

Constructor Summary

Constructors

Constructor and Description
AbstractFunction()

Method Summary

Modifier and Type	Method and Description
AtomicSequence	atomize() Atomize the item.
boolean	deepEquals(Function other, XPathContext context, AtomicComparer comparer, int flags) Test whether this FunctionItem is deep-equal to another function item, under the rules of the deep-equal function
boolean	effectiveBooleanValue() Get the effective boolean value of the function item
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).
OperandRole[]	getOperandRoles() Get the roles of the arguments, for the purposes of streaming
UnicodeString	getUnicodeStringValue() Get the string value of the function
boolean	isArray() Ask whether this function is an array
boolean	isMap() Ask whether this function is a map
boolean	isTrustedResultType() Check that result type is SystemFunction or AtomicConstructorFunction
XPathContext	makeNewContext(XPathContext callingContext, ContextOriginator originator) Prepare an XPathContext object for evaluating the function
void	simplify()
java.lang.String	toShortString() Provide a short string showing the contents of the item, suitable for use in error messages
void	typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) Type check the function (may modify it by adding code for converting the arguments)

Methods inherited from class java.lang.Object

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

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

getArity, getDescription, getFunctionItemType, getFunctionName, getGenre, 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

Methods inherited from interface net.sf.saxon.expr.Callable

call

Constructor Detail

AbstractFunction

public AbstractFunction()

Method Detail

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 is an array

Specified by:

isArray in interface Function

Returns:

true if this function item is an array, otherwise false

isMap

public boolean isMap()

Ask whether this function is a map

Specified by:

isMap in interface Function

Returns:

true if this function item is a map, otherwise false

getUnicodeStringValue

public UnicodeString getUnicodeStringValue()

Get the string value of the function

Specified by:

getUnicodeStringValue in interface GroundedValue

Specified by:

getUnicodeStringValue in interface Item

Returns:

nothing; this method always throws an exception

Throws:

java.lang.UnsupportedOperationException - (the string value of a function is not defined)

getAnnotations

public AnnotationList getAnnotations()

Description copied from interface: Function

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

effectiveBooleanValue

public boolean effectiveBooleanValue()
                              throws XPathException

Get the effective boolean value of the function item

Specified by:

effectiveBooleanValue in interface GroundedValue

Returns:

the effective boolean value

Throws:

XPathException - (the EBVof a function item is not defined)

simplify

public void simplify()
              throws XPathException

Throws:

XPathException

typeCheck

public void typeCheck(ExpressionVisitor visitor,
                      ContextItemStaticInfo contextItemType)
               throws XPathException

Type check the function (may modify it by adding code for converting the arguments)

Parameters:

visitor - the expression visitor, supplies context information

contextItemType - the context item type at the point where the function definition appears

Throws:

XPathException - if any failure (e.g. a type checking failure) occurs

makeNewContext

public XPathContext makeNewContext(XPathContext callingContext,
                                   ContextOriginator originator)

Prepare an XPathContext object for evaluating the function

Specified by:

makeNewContext in interface Function

Parameters:

callingContext - the XPathContext of the function calling expression

originator - the originator of the new context

Returns:

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

deepEquals

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

Test whether this FunctionItem is deep-equal to another function item, 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 function items are deep-equal

Throws:

XPathException - if the comparison cannot be performed

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

Parameters:

out - the destination for the information

Throws:

XPathException - if things go wrong

isTrustedResultType

public boolean isTrustedResultType()

Check that result type is SystemFunction or AtomicConstructorFunction

Specified by:

isTrustedResultType in interface Function

Returns:

true if the implementation can be trusted

toShortString

public java.lang.String toShortString()

Description copied from interface: Function

Provide a short string showing the contents of the item, suitable for use in error messages

Specified by:

toShortString in interface Function

Specified by:

toShortString in interface GroundedValue

Specified by:

toShortString in interface Item

Returns:

a depiction of the item suitable for use in error messages