net.sf.saxon.functions
Class StartsWith

java.lang.Object
  extended by net.sf.saxon.expr.Expression
      extended by net.sf.saxon.expr.FunctionCall
          extended by net.sf.saxon.functions.SystemFunction
              extended by net.sf.saxon.functions.CollatingFunction
                  extended by net.sf.saxon.functions.StartsWith
All Implemented Interfaces:
Serializable, SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, InstructionInfo, Locator

public class StartsWith
extends CollatingFunction

Implements the fn:starts-with() function

See Also:
Serialized Form

Field Summary
 
Fields inherited from class net.sf.saxon.functions.CollatingFunction
stringCollator
 
Fields inherited from class net.sf.saxon.functions.SystemFunction
operation
 
Fields inherited from class net.sf.saxon.expr.FunctionCall
argument
 
Fields inherited from class net.sf.saxon.expr.Expression
EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, PUSH_SELECTION, staticProperties, WATCH_METHOD
 
Constructor Summary
StartsWith()
           
 
Method Summary
 boolean effectiveBooleanValue(XPathContext context)
          Get the effective boolean value of the expression.
 Item evaluateItem(XPathContext context)
          Evaluate the function
 
Methods inherited from class net.sf.saxon.functions.CollatingFunction
checkArguments, copy, getAbsoluteCollationURI, getAtomicComparer, getCollator, getExpressionBaseURI, getStringCollator
 
Methods inherited from class net.sf.saxon.functions.SystemFunction
addContextDocumentArgument, addDocToPathMap, computeCardinality, computeSpecialProperties, getDetails, getErrorCodeForTypeErrors, getImplementationMethod, getItemType, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault
 
Methods inherited from class net.sf.saxon.expr.FunctionCall
addExternalFunctionCallToPathMap, checkArgumentCount, equals, 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, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterate, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, process, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
 
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
 

Constructor Detail

StartsWith

public StartsWith()
Method Detail

effectiveBooleanValue

public boolean effectiveBooleanValue(XPathContext context)
                              throws XPathException
Get the effective boolean value of the expression. This returns false if the value is the empty sequence, a zero-length string, a number equal to zero, or the boolean false. Otherwise it returns true.

Overrides:
effectiveBooleanValue in class Expression
Parameters:
context - 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

evaluateItem

public Item evaluateItem(XPathContext context)
                  throws XPathException
Evaluate the function

Specified by:
evaluateItem in interface EvaluableItem
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


Copyright (c) 2004-2010 Saxonica Limited. All rights reserved.