net.sf.saxon.functions

Class StringJoin

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.FunctionCall

net.sf.saxon.functions.SystemFunctionCall

net.sf.saxon.functions.FoldingFunction

net.sf.saxon.functions.StringJoin

All Implemented Interfaces:

SourceLocator, Callable, IdentityComparable, InstructionInfo

public class StringJoin
extends FoldingFunction

fn:string-join(string* $sequence, string $separator)

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, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD

Constructor Summary

Constructors

Constructor and Description
StringJoin()

Method Summary

Methods

Modifier and Type	Method and Description
int	computeCardinality() Determine the cardinality of the function.
Expression	copy() Copy an expression.
boolean	equals(Object o) Determine whether two expressions are equivalent
ExpressionCompiler	getExpressionCompiler() Return the compiler of the StringJoin expression
Fold	getFold(XPathContext context, Sequence... additionalArguments) Create the Fold object which actually performs the evaluation.
int	getImplementationMethod() Get implementation method
boolean	isReturnEmptyIfEmpty()
Expression	optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) Perform optimisation of an expression and its subexpressions.
void	process(XPathContext context) Process the instruction in push mode.
void	setReturnEmptyIfEmpty(boolean option) Indicate that when the input sequence (first argument) is empty, the function should return an empty sequence rather than an empty string

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

call, evaluateItem, getStreamingAdjunct, iterate

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

addContextDocumentArgument, addDocToPathMap, bindStaticContext, checkArguments, computeSpecialProperties, equalOrNull, getContextNode, getConvertingCallable, getDefaultArgumentNode, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getItemType, getOperation, getRequiredType, makeSystemFunction, operands, setDetails, toShortString, useContextItemAsDefault

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

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

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

addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, clearStreamabilityData, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluateAsString, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getConfiguration, getConstructType, getContainer, getDependencies, getEvaluationMethod, getHostLanguage, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLocationId, getObjectName, getPosture, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getStreamability, getSweep, getSystemId, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isIdentical, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, makeStreamingAdjunct, markTailFunctionCalls, operandList, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, setPostureAndSweep, simplify, staticTypeCheck, suppressValidation, toPattern, toStreamingPattern, typeError, unordered

Methods inherited from class java.lang.Object

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

Constructor Detail

StringJoin

public StringJoin()

Method Detail

setReturnEmptyIfEmpty

public void setReturnEmptyIfEmpty(boolean option)

Indicate that when the input sequence (first argument) is empty, the function should return an empty sequence rather than an empty string

Parameters:

option - true if an empty sequence should be returned when the input is an empty sequence.

isReturnEmptyIfEmpty

public boolean isReturnEmptyIfEmpty()

computeCardinality

public int computeCardinality()

Determine the cardinality of the function.

Overrides:

computeCardinality in class SystemFunctionCall

Returns:

the computed cardinality, as one of the values StaticProperty.ALLOWS_ZERO_OR_ONE, StaticProperty.EXACTLY_ONE, StaticProperty.ALLOWS_ONE_OR_MORE, StaticProperty.ALLOWS_ZERO_OR_MORE

copy

public Expression copy()

Description copied from class: SystemFunctionCall

Copy an expression. This makes a deep copy.

Overrides:

copy in class SystemFunctionCall

Returns:

the copy of the original expression

equals

public boolean equals(Object o)

Determine whether two expressions are equivalent

Overrides:

equals in class SystemFunctionCall

getImplementationMethod

public int getImplementationMethod()

Description copied from class: FoldingFunction

Get implementation method

Overrides:

getImplementationMethod in class FoldingFunction

Returns:

a value that indicates this function is capable of being streamed

optimize

public Expression optimize(ExpressionVisitor visitor,
                  ContextItemStaticInfo contextItemType)
                    throws XPathException

Description copied from class: SystemFunctionCall

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)

getFold

public Fold getFold(XPathContext context,
           Sequence... additionalArguments)
             throws XPathException

Description copied from class: FoldingFunction

Create the Fold object which actually performs the evaluation. Must be implemented in every subclass.

Specified by:

getFold in class FoldingFunction

Parameters:

context - the dynamic evaluation context

additionalArguments - the values of all arguments other than the first.

Returns:

the Fold object used to compute the function

Throws:

XPathException - if a dynamic error occurs

process

public void process(XPathContext context)
             throws XPathException

Process the instruction in push mode. This avoids constructing the concatenated string in memory, instead its parts can be sent straight to the serializer.

Overrides:

process in class Expression

Parameters:

context - The dynamic context, giving access to the current node, the current variables, etc.

Throws:

XPathException - if a dynamic error occurs

getExpressionCompiler

public ExpressionCompiler getExpressionCompiler()

Return the compiler of the StringJoin expression

Overrides:

getExpressionCompiler in class Expression

Returns:

the relevant ExpressionCompiler