net.sf.saxon.functions

Class NotFn

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.FunctionCall

net.sf.saxon.functions.SystemFunctionCall

net.sf.saxon.functions.NotFn

All Implemented Interfaces:

Serializable, SourceLocator, LocationProvider, SaxonLocator, Callable, Negatable, InstructionInfo, Locator

public class NotFn
extends SystemFunctionCall
implements Negatable

This class supports the XPath functions boolean(), not(), true(), and false()

See Also:

Serialized Form

Field Summary

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

operation

Fields inherited from class net.sf.saxon.expr.FunctionCall

argument

Fields inherited from class net.sf.saxon.expr.Expression

EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, INHERITED_CONTEXT, INSPECTION_CONTEXT, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, NAVIGATION_CONTEXT, NODE_VALUE_CONTEXT, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, W3C_CONSUMING, W3C_FREE_RANGING, W3C_GROUP_CONSUMING, W3C_MOTIONLESS, WATCH_METHOD

Constructor Summary

Constructors

Constructor and Description
NotFn()

Method Summary

Methods

Modifier and Type	Method and Description
Sequence	call(XPathContext context, Sequence[] arguments) Evaluate the expression
void	checkArguments(ExpressionVisitor visitor) Static analysis: prevent sorting of the argument
boolean	effectiveBooleanValue(XPathContext c) Evaluate the effective boolean value
BooleanValue	evaluateItem(XPathContext context) Evaluate the function
ExpressionCompiler	getExpressionCompiler() Return the compiler of the NotFn expression
boolean	isNegatable(ExpressionVisitor visitor) Check whether this specific instance of the expression is negatable
Expression	negate() Create an expression that returns the negation of this expression
Expression	optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) Perform optimisation of an expression and its subexpressions.

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

addContextDocumentArgument, addDocToPathMap, bindStaticContext, computeCardinality, computeSpecialProperties, copy, equalOrNull, equals, getContextNode, getConvertingCallable, getDefaultArgumentNode, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getImplementationMethod, getItemType, getOperation, getRequiredType, iterateSubExpressionInfo, makeSystemFunction, setDetails, useContextItemAsDefault

Methods inherited from class net.sf.saxon.expr.FunctionCall

addExternalFunctionCallToPathMap, checkArgumentCount, explain, getArguments, getDisplayName, getExpressionName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, preEvaluate, promote, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString, typeCheck

Methods inherited from class net.sf.saxon.expr.Expression

addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getHostLanguage, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getStreamability, getStreamingAdjunct, getSystemId, getSystemId, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, iterateEvents, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toPattern, toStreamingPattern, typeError

Methods inherited from class java.lang.Object

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

Constructor Detail

NotFn

public NotFn()

Method Detail

checkArguments

public void checkArguments(ExpressionVisitor visitor)
                    throws XPathException

Static analysis: prevent sorting of the argument

Overrides:

checkArguments in class SystemFunctionCall

Parameters:

visitor - the expression visitor

Throws:

XPathException - if the arguments are incorrect

optimize

public Expression optimize(ExpressionVisitor visitor,
                  ExpressionVisitor.ContextItemType contextItemType)
                    throws XPathException

Perform optimisation of an expression and its subexpressions.

This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.

Overrides:

optimize in class SystemFunctionCall

Parameters:

visitor - an expression visitor

contextItemType - the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to Type.ITEM_TYPE

Returns:

the original expression, rewritten if appropriate to optimize execution

Throws:

XPathException - if an error is discovered during this phase (typically a type error)

isNegatable

public boolean isNegatable(ExpressionVisitor visitor)

Check whether this specific instance of the expression is negatable

Specified by:

isNegatable in interface Negatable

Returns:

true if it is

negate

public Expression negate()

Create an expression that returns the negation of this expression

Specified by:

negate in interface Negatable

Returns:

the negated expression

evaluateItem

public BooleanValue evaluateItem(XPathContext context)
                          throws XPathException

Evaluate the function

Overrides:

evaluateItem in class Expression

Parameters:

context - The context in which the expression is to be evaluated

Returns:

the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence

Throws:

XPathException - if any dynamic error occurs evaluating the expression

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext c)
                              throws XPathException

Evaluate the effective boolean value

Overrides:

effectiveBooleanValue in class Expression

Parameters:

c - The context in which the expression is to be evaluated

Returns:

the effective boolean value

Throws:

XPathException - if any dynamic error occurs evaluating the expression

call

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

Evaluate the expression

Specified by:

call in interface Callable

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

getExpressionCompiler

public ExpressionCompiler getExpressionCompiler()

Return the compiler of the NotFn expression

Overrides:

getExpressionCompiler in class Expression

Returns:

the relevant ExpressionCompiler