net.sf.saxon.functions

Class ApplyFn

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.ApplyFn

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

public class ApplyFn
extends SystemFunction

This class implements the function fn:apply(), which is a standard function in XQuery 3.1. The fn:apply function is also used internally to implement dynamic function calls.

Constructor Summary

Constructors

Constructor and Description
ApplyFn()

Method Summary

Modifier and Type	Method and Description
Sequence	call(XPathContext context, Sequence[] arguments) Evaluate the expression
void	exportAttributes(ExpressionPresenter out) Export any context attributes held within the SystemFunction object.
ItemType	getResultItemType(Expression[] args) Get the return type, given knowledge of the actual arguments
void	importAttributes(java.util.Properties attributes) Import any attributes found in the export file, that is, any attributes output using the exportAttributes method
boolean	isDynamicFunctionCall() Ask whether this call to fn:apply was originally written as a dynamic function call
Expression	makeOptimizedFunctionCall(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo, Expression... arguments) Allow the function to create an optimized call based on the values of the actual arguments
void	setDynamicFunctionCall(java.lang.String fnExpr) Say that this call to fn:apply was originally written as a dynamic function call

Methods inherited from class net.sf.saxon.functions.SystemFunction

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, fixArguments, getArity, getCardinality, getCompilerName, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, isTrustedResultType, makeCall, makeFunction, makeFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, typeCheckCaller

Methods inherited from class net.sf.saxon.functions.AbstractFunction

atomize, deepEquals, effectiveBooleanValue, getAnnotations, getStringValue, getStringValueCS, isArray, isMap, makeNewContext, simplify, typeCheck

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

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

Methods inherited from class java.lang.Object

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

Constructor Detail

ApplyFn

public ApplyFn()

Method Detail

setDynamicFunctionCall

public void setDynamicFunctionCall(java.lang.String fnExpr)

Say that this call to fn:apply was originally written as a dynamic function call

Parameters:

fnExpr - string representation of the expression used as the dynamic call

isDynamicFunctionCall

public boolean isDynamicFunctionCall()

Ask whether this call to fn:apply was originally written as a dynamic function call

Returns:

true if it was originally a dynamic function call

getResultItemType

public ItemType getResultItemType(Expression[] args)

Get the return type, given knowledge of the actual arguments

Overrides:

getResultItemType in class SystemFunction

Parameters:

args - the actual arguments supplied

Returns:

the best available item type that the function will return

makeOptimizedFunctionCall

public Expression makeOptimizedFunctionCall(ExpressionVisitor visitor,
                                            ContextItemStaticInfo contextInfo,
                                            Expression... arguments)
                                     throws XPathException

Description copied from class: SystemFunction

Allow the function to create an optimized call based on the values of the actual arguments

Overrides:

makeOptimizedFunctionCall in class SystemFunction

Parameters:

visitor - the expression visitor

contextInfo - information about the context item

arguments - the supplied arguments to the function call. Note: modifying the contents of this array should not be attempted, it is likely to have no effect.

Returns:

either a function call on this function, or an expression that delivers the same result, or null indicating that no optimization has taken place

Throws:

XPathException - if an error is detected

call

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

Evaluate the expression

Parameters:

context - the dynamic evaluation context

arguments - the values of the arguments. The first argument is the function item to be called; the second argument is an array containing the arguments to be passed to that function, before conversion.

Returns:

the result of the evaluation, in the form of a SequenceIterator

Throws:

XPathException - if a dynamic error occurs during the evaluation of the expression

exportAttributes

public void exportAttributes(ExpressionPresenter out)

Description copied from class: SystemFunction

Export any context attributes held within the SystemFunction object. The implementation will normally make one or more calls on out.emitAttribute(name, value).

Overrides:

exportAttributes in class SystemFunction

Parameters:

out - the export destination

importAttributes

public void importAttributes(java.util.Properties attributes)
                      throws XPathException

Import any attributes found in the export file, that is, any attributes output using the exportAttributes method

Overrides:

importAttributes in class SystemFunction

Parameters:

attributes - the attributes, as a properties object

Throws:

XPathException