net.sf.saxon.functions

Class AccessorFn

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.ScalarSystemFunction

net.sf.saxon.functions.AccessorFn

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

Direct Known Subclasses:

AccessorFn.DayFromDate, AccessorFn.DayFromDateTime, AccessorFn.DaysFromDuration, AccessorFn.HoursFromDateTime, AccessorFn.HoursFromDuration, AccessorFn.HoursFromTime, AccessorFn.LocalNameFromQName, AccessorFn.MinutesFromDateTime, AccessorFn.MinutesFromDuration, AccessorFn.MinutesFromTime, AccessorFn.MonthFromDate, AccessorFn.MonthFromDateTime, AccessorFn.MonthsFromDuration, AccessorFn.NamespaceUriFromQName, AccessorFn.PrefixFromQName, AccessorFn.SecondsFromDateTime, AccessorFn.SecondsFromDuration, AccessorFn.SecondsFromTime, AccessorFn.TimezoneFromDate, AccessorFn.TimezoneFromDateTime, AccessorFn.TimezoneFromTime, AccessorFn.YearFromDate, AccessorFn.YearFromDateTime, AccessorFn.YearsFromDuration

public abstract class AccessorFn
extends ScalarSystemFunction

This class supports the get_X_from_Y functions defined in XPath 2.0

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	AccessorFn.Component
static class	AccessorFn.DayFromDate
static class	AccessorFn.DayFromDateTime
static class	AccessorFn.DaysFromDuration
static class	AccessorFn.HoursFromDateTime
static class	AccessorFn.HoursFromDuration
static class	AccessorFn.HoursFromTime
static class	AccessorFn.LocalNameFromQName
static class	AccessorFn.MinutesFromDateTime
static class	AccessorFn.MinutesFromDuration
static class	AccessorFn.MinutesFromTime
static class	AccessorFn.MonthFromDate
static class	AccessorFn.MonthFromDateTime
static class	AccessorFn.MonthsFromDuration
static class	AccessorFn.NamespaceUriFromQName
static class	AccessorFn.PrefixFromQName
static class	AccessorFn.SecondsFromDateTime
static class	AccessorFn.SecondsFromDuration
static class	AccessorFn.SecondsFromTime
static class	AccessorFn.TimezoneFromDate
static class	AccessorFn.TimezoneFromDateTime
static class	AccessorFn.TimezoneFromTime
static class	AccessorFn.YearFromDate
static class	AccessorFn.YearFromDateTime
static class	AccessorFn.YearsFromDuration

Field Summary

Fields inherited from class net.sf.saxon.functions.ScalarSystemFunction

ZERO_LENGTH_STRING

Constructor Summary

Constructors

Constructor and Description
AccessorFn()

Method Summary

Modifier and Type	Method and Description
AtomicValue	evaluate(Item item, XPathContext context) Evaluate the expression
java.lang.String	getCompilerName() Get the (local) name of a class that can be used to generate bytecode for this system function
abstract AccessorFn.Component	getComponentId()
IntegerValue[]	getIntegerBounds() For an expression that returns an integer or a sequence of integers, get a lower and upper bound on the values of the integers that may be returned, from static analysis.
int	getRequiredComponent() Get the required component

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

call, makeFunctionCall, resultWhenEmpty

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

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, importAttributes, isTrustedResultType, makeCall, makeFunction, makeOptimizedFunctionCall, 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

AccessorFn

public AccessorFn()

Method Detail

getComponentId

public abstract AccessorFn.Component getComponentId()

getIntegerBounds

public IntegerValue[] getIntegerBounds()

For an expression that returns an integer or a sequence of integers, get a lower and upper bound on the values of the integers that may be returned, from static analysis. The default implementation returns null, meaning "unknown" or "not applicable". Other implementations return an array of two IntegerValue objects, representing the lower and upper bounds respectively. The values UNBOUNDED_LOWER and UNBOUNDED_UPPER are used by convention to indicate that the value may be arbitrarily large. The values MAX_STRING_LENGTH and MAX_SEQUENCE_LENGTH are used to indicate values limited by the size of a string or the size of a sequence.

Overrides:

getIntegerBounds in class SystemFunction

Returns:

the lower and upper bounds of integer values in the result, or null to indicate unknown or not applicable.

getRequiredComponent

public int getRequiredComponent()

Get the required component

Returns:

the integer code identifying of the required component

evaluate

public AtomicValue evaluate(Item item,
                            XPathContext context)
                     throws XPathException

Evaluate the expression

Specified by:

evaluate in class ScalarSystemFunction

Parameters:

item - the supplied argument

context - the dynamic context

Returns:

the result of the evaluation

Throws:

XPathException - if a dynamic error occurs

getCompilerName

public java.lang.String getCompilerName()

Description copied from class: SystemFunction

Get the (local) name of a class that can be used to generate bytecode for this system function

Overrides:

getCompilerName in class SystemFunction

Returns:

the name of a bytecode generation class, or null if there is no bytecode support for this function