net.sf.saxon.functions
Class StringFn

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.expr.FunctionCall
          net.sf.saxon.functions.SystemFunction
              net.sf.saxon.functions.StringFn

All Implemented Interfaces:

Serializable, SourceLocator, LocationProvider, SaxonLocator, EvaluableItem, SequenceIterable, DivisibleInstruction, InstructionInfo, Locator

public class StringFn
extends SystemFunction
implements DivisibleInstruction

Implement XPath function string()

See Also:

Serialized Form

Field Summary

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, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties

Constructor Summary

StringFn()

Method Summary

PathMap.PathMapNodeSet	addDocToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodes) Add a representation of a doc() call or similar function to a PathMap.
Item	evaluateItem(XPathContext c) Evaluate the function
void	processLeft(Stack<XPathContext> contextStack, Stack state) In streaming mode, process the first half of the instruction (for example, to start a new document or element)
void	processRight(Stack<XPathContext> contextStack, Stack state) In streaming mode, process the right half of the instruction (for example, to end a new document or element) Note that unlike other divisible instructions this one doesn't push the result to the current output destination, it leaves a sequenceIterator over the result on the stack.
Expression	simplify(ExpressionVisitor visitor) Simplify and validate.

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

addContextDocumentArgument, checkArguments, computeCardinality, computeSpecialProperties, copy, getDetails, getErrorCodeForTypeErrors, getItemType, getRequiredType, makeSystemFunction, optimize, setDetails, useContextItemAsDefault

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

addExternalFunctionCallToPathMap, checkArgumentCount, equals, explain, getArguments, getDisplayName, 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, getExecutable, getHostLanguage, getImplementationMethod, 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, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError

Methods inherited from class java.lang.Object

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

Constructor Detail

StringFn

public StringFn()

Method Detail

simplify

public Expression simplify(ExpressionVisitor visitor)
                    throws XPathException

Simplify and validate. This is a pure function so it can be simplified in advance if the arguments are known

Overrides:

simplify in class FunctionCall

Parameters:

visitor - an expression visitor

Returns:

the simplified expression

Throws:

XPathException - if an error is discovered during expression rewriting

addDocToPathMap

public PathMap.PathMapNodeSet addDocToPathMap(PathMap pathMap,
                                              PathMap.PathMapNodeSet pathMapNodes)

Add a representation of a doc() call or similar function to a PathMap. This is a convenience method called by the addToPathMap() methods for doc(), document(), collection() and similar functions. These all create a new root expression in the path map.

Overrides:

addDocToPathMap in class SystemFunction

Parameters:

pathMap - the PathMap to which the expression should be added

pathMapNodes - the node in the PathMap representing the focus at the point where this expression is called. Set to null if this expression appears at the top level.

Returns:

the pathMapNode representing the focus established by this expression, in the case where this expression is the first operand of a path expression or filter expression

evaluateItem

public Item evaluateItem(XPathContext c)
                  throws XPathException

Evaluate the function

Specified by:

evaluateItem in interface EvaluableItem

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

processLeft

public void processLeft(Stack<XPathContext> contextStack,
                        Stack state)
                 throws XPathException

In streaming mode, process the first half of the instruction (for example, to start a new document or element)

Specified by:

processLeft in interface DivisibleInstruction

Parameters:

contextStack -

state - a stack on which the instruction can save state information during the call on processLeft()

Throws:

XPathException

processRight

public void processRight(Stack<XPathContext> contextStack,
                         Stack state)
                  throws XPathException

In streaming mode, process the right half of the instruction (for example, to end a new document or element) Note that unlike other divisible instructions this one doesn't push the result to the current output destination, it leaves a sequenceIterator over the result on the stack.

Specified by:

processRight in interface DivisibleInstruction

Parameters:

contextStack -

state - a stack on which the instruction can save state information during the call on processLeft()

Throws:

XPathException