net.sf.saxon.functions

Class GenerateId

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.FunctionCall

net.sf.saxon.functions.SystemFunctionCall

net.sf.saxon.functions.GenerateId

All Implemented Interfaces:

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

public class GenerateId
extends SystemFunctionCall

This class supports the generate-id() function

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
GenerateId()

Method Summary

Methods

Modifier and Type	Method and Description
Sequence	call(XPathContext context, Sequence[] arguments) Evaluate the expression
int	computeSpecialProperties() Determine the special properties of this expression.
StringValue	evaluateItem(XPathContext c) Evaluate the function in a string context
static StringValue	generateId(NodeInfo node)
ExpressionCompiler	getExpressionCompiler() Return the compiler of the GenerateId expression
Expression	simplify(ExpressionVisitor visitor) Simplify and validate.

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

addContextDocumentArgument, addDocToPathMap, bindStaticContext, checkArguments, computeCardinality, copy, equalOrNull, equals, getContextNode, getConvertingCallable, getDefaultArgumentNode, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getImplementationMethod, getItemType, getOperation, getRequiredType, iterateSubExpressionInfo, makeSystemFunction, optimize, 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, simplifyArguments, toString, typeCheck

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

addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, 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

GenerateId

public GenerateId()

Method Detail

simplify

public Expression simplify(ExpressionVisitor visitor)
                    throws XPathException

Simplify and validate.

Overrides:

simplify in class FunctionCall

Parameters:

visitor - an expression visitor

Returns:

the simplified expression

Throws:

XPathException - if an error is discovered during expression rewriting

computeSpecialProperties

public int computeSpecialProperties()

Determine the special properties of this expression. The generate-id() function is a special case: it is considered creative if its operand is creative, so that generate-id(f()) is not taken out of a loop

Overrides:

computeSpecialProperties in class SystemFunctionCall

Returns:

the special properties, as a bit-significant integer

evaluateItem

public StringValue evaluateItem(XPathContext c)
                         throws XPathException

Evaluate the function in a string context

Overrides:

evaluateItem in class Expression

Parameters:

c - 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

generateId

public static StringValue generateId(NodeInfo node)

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

getExpressionCompiler

public ExpressionCompiler getExpressionCompiler()

Return the compiler of the GenerateId expression

Overrides:

getExpressionCompiler in class Expression

Returns:

the relevant ExpressionCompiler