Package net.sf.saxon.functions

Class ContextAccessorFunction

java.lang.Object

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.ContextAccessorFunction

All Implemented Interfaces:

Callable, FunctionItem, GroundedValue, Item, Sequence

Direct Known Subclasses:

ContextItemAccessorFunction, CurrentGroup, CurrentGroupingKey, CurrentOutputUri, FunctionLookup, PositionAndLast, RegexGroup

public abstract class ContextAccessorFunction
extends SystemFunction

A ContextAccessorFunction is a function that is dependent on the dynamic context. In the case of dynamic function calls, the context is bound at the point where the function is created, not at the point where the function is called.

Constructor Summary

Constructors

Constructor	Description
ContextAccessorFunction()

Method Summary

Modifier and Type	Method	Description
abstract FunctionItem	bindContext(XPathContext context)	Bind context information to appear as part of the function's closure.
Sequence	call(XPathContext context, Sequence[] arguments)	Evaluate the expression

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

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getContextNode, getDescription, getDetails, getElaborator, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, getUniStringArg, hashCode, importAttributes, isSequenceVariadic, isTrustedResultType, makeCall, makeFunction, makeFunction40, makeFunctionCall, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, toShortString, toString, typeCheckCaller

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

atomize, deepEqual40, deepEquals, effectiveBooleanValue, getAnnotations, getUnicodeStringValue, isArray, isMap, makeNewContext, simplify, typeCheck

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

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

getGenre

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

asIterable, concatenate, containsNode, materialize

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.Sequence

makeRepeatable

Constructor Detail

ContextAccessorFunction

public ContextAccessorFunction()

Method Detail

bindContext

public abstract FunctionItem bindContext(XPathContext context)
                                  throws XPathException

Bind context information to appear as part of the function's closure. If this method has been called, the supplied context will be used in preference to the context at the point where the function is actually called.

Parameters:

context - the context to which the function applies. Must not be null.

Throws:

XPathException

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, supplied as Sequences

Returns:

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

Throws:

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