Class TreatFn

java.lang.Object

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.functions.TreatFn

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

Direct Known Subclasses:

TreatFn.ExactlyOne, TreatFn.OneOrMore, TreatFn.ZeroOrOne

public abstract class TreatFn
extends SystemFunction
implements Callable

This class supports the XPath 2.0 functions exactly-one(), one-or-more(), zero-or-one(). Because Saxon doesn't do strict static type checking, these are essentially identity functions; the run-time type checking is done as part of the function call mechanism

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	TreatFn.ExactlyOne
static class	TreatFn.OneOrMore
static class	TreatFn.ZeroOrOne

Constructor Summary

Constructors

Constructor	Description
TreatFn()

Method Summary

Modifier and Type	Method	Description
Sequence	call(XPathContext context, Sequence[] arguments)	Invoke the function
abstract String	getErrorCodeForTypeErrors()	Return the error code to be used for type errors
abstract int	getRequiredCardinality()
String	getStreamerName()	Get a name that identifies the class that can be used to evaluate this function in streaming mode, that is, supplying one item or event at a time as it is delivered by the parser.
RoleDiagnostic	makeRoleDiagnostic()

Methods inherited from class SystemFunction

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

Methods inherited from class AbstractFunction

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

Methods inherited from class Object

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

Methods inherited from interface Function

getGenre

Methods inherited from interface GroundedValue

asIterable, concatenate, containsNode, materialize

Methods inherited from interface Item

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

Methods inherited from interface Sequence

makeRepeatable

Constructor Details

TreatFn

public TreatFn()

Method Details

getErrorCodeForTypeErrors

public abstract String getErrorCodeForTypeErrors()

Return the error code to be used for type errors

Overrides:

getErrorCodeForTypeErrors in class SystemFunction

Returns:

the error code to be used for type errors in the function call. Normally XPTY0004, but different codes are used for functions such as exactly-one()

getRequiredCardinality

public abstract int getRequiredCardinality()

call

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

Description copied from interface: Function

Invoke the function

Specified by:

call in interface Callable

Specified by:

call in interface Function

Parameters:

context - the XPath dynamic evaluation context

arguments - the actual arguments to be supplied

Returns:

the result of invoking the function

Throws:

XPathException - if a dynamic error occurs within the function

makeRoleDiagnostic

public RoleDiagnostic makeRoleDiagnostic()

getStreamerName

public String getStreamerName()

Description copied from class: SystemFunction

Get a name that identifies the class that can be used to evaluate this function in streaming mode, that is, supplying one item or event at a time as it is delivered by the parser. Special streaming support is generally available in Saxon-EE for all system functions that take a sequence as their argument.

Overrides:

getStreamerName in class SystemFunction

Returns:

a name that identifies a class that supports streamed evaluation of this system function, or null if no such class is available. The mapping of names to classes is defined in the Saxon-EE class StreamerMap. In non-streaming Saxon editions (HE and PE) the method always returns null.