net.sf.saxon.expr.instruct

Class NamespaceConstructor

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.instruct.Instruction

net.sf.saxon.expr.instruct.SimpleNodeConstructor

net.sf.saxon.expr.instruct.NamespaceConstructor

All Implemented Interfaces:

SourceLocator, TailCallReturner, IdentityComparable, InstructionInfo

public class NamespaceConstructor
extends SimpleNodeConstructor

A namespace constructor instruction. (xsl:namespace in XSLT 2.0, or namespace{}{} in XQuery 1.1)

Field Summary

Fields inherited from class net.sf.saxon.expr.instruct.SimpleNodeConstructor

select

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
NamespaceConstructor(Expression name) Create an xsl:namespace instruction for dynamic construction of namespace nodes

Method Summary

Methods

Modifier and Type	Method and Description
Expression	copy() Copy an expression.
NodeInfo	evaluateItem(XPathContext context) Evaluate as an expression.
NodeName	evaluateNodeName(XPathContext context) Run-time method to compute the name of the node being constructed.
void	explain(ExpressionPresenter out) Diagnostic print of expression structure.
int	getCardinality() Determine the static cardinality of the expression.
ExpressionCompiler	getExpressionCompiler() Return the compiler of the NamespaceConstructor expression
int	getInstructionNameCode() Set the name of this instruction for diagnostic and tracing purposes
ItemType	getItemType() Get the item type of the items returned by evaluating this instruction
Expression	getNameExpression() Get the expression that defines the namespace node's name
void	localTypeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) Method to perform type-checking specific to the kind of instruction
Iterable<Operand>	operands() Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression.
void	processValue(CharSequence value, XPathContext context) Process the value of the node, to create the new node.
protected void	promoteInst(PromotionOffer offer) Offer promotion for subexpressions.
boolean	replaceOperand(Expression original, Expression replacement) Replace one subexpression by a replacement subexpression

Methods inherited from class net.sf.saxon.expr.instruct.SimpleNodeConstructor

checkContent, computeCardinality, computeSpecialProperties, createsNewNodes, getContentExpression, getStreamingAdjunct, iterate, optimize, processLeavingTail, setSelect, typeCheck

Methods inherited from class net.sf.saxon.expr.instruct.Instruction

assembleParams, assembleTunnelParams, dynamicError, evaluateAsString, getConstructType, getExpressionName, getImplementationMethod, getInstructionName, getIteratorFromProcessMethod, getSourceLocator, isXSLT, process, promote, toStreamingPattern

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

addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, clearStreamabilityData, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, getColumnNumber, getConfiguration, 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, toShortString, toString, typeError, unordered

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface javax.xml.transform.SourceLocator

getColumnNumber, getLineNumber, getPublicId, getSystemId

Constructor Detail

NamespaceConstructor

public NamespaceConstructor(Expression name)

Create an xsl:namespace instruction for dynamic construction of namespace nodes

Parameters:

name - the expression to evaluate the name of the node (that is, the prefix)

Method Detail

getNameExpression

public Expression getNameExpression()

Get the expression that defines the namespace node's name

Returns:

the expression that defines the namespace node's name (that is, the namespace prefix)

getInstructionNameCode

public int getInstructionNameCode()

Set the name of this instruction for diagnostic and tracing purposes

Overrides:

getInstructionNameCode in class Instruction

Returns:

a code identifying the instruction: typically but not always the fingerprint of a name in the XSLT namespace

getItemType

public ItemType getItemType()

Description copied from class: Instruction

Get the item type of the items returned by evaluating this instruction

Overrides:

getItemType in class Instruction

Returns:

the static item type of the instruction

getCardinality

public int getCardinality()

Description copied from class: Expression

Determine the static cardinality of the expression. This establishes how many items there will be in the result of the expression, at compile time (i.e., without actually evaluating the result.

Overrides:

getCardinality in class Expression

Returns:

one of the values Cardinality.ONE_OR_MORE, Cardinality.ZERO_OR_MORE, Cardinality.EXACTLY_ONE, Cardinality.ZERO_OR_ONE, Cardinality.EMPTY. This default implementation returns ZERO_OR_MORE (which effectively gives no information).

promoteInst

protected void promoteInst(PromotionOffer offer)
                    throws XPathException

Description copied from class: SimpleNodeConstructor

Offer promotion for subexpressions. The offer will be accepted if the subexpression is not dependent on the factors (e.g. the context item) identified in the PromotionOffer. By default the offer is not accepted - this is appropriate in the case of simple expressions such as constant values and variable references where promotion would give no performance advantage. This method is always called at compile time.

Overrides:

promoteInst in class SimpleNodeConstructor

Parameters:

offer - details of the offer, for example the offer to move expressions that don't depend on the context to an outer level in the containing expression

Throws:

XPathException - if any error is detected

localTypeCheck

public void localTypeCheck(ExpressionVisitor visitor,
                  ContextItemStaticInfo contextItemType)
                    throws XPathException

Description copied from class: SimpleNodeConstructor

Method to perform type-checking specific to the kind of instruction

Specified by:

localTypeCheck in class SimpleNodeConstructor

Parameters:

visitor - an expression visitor

contextItemType - the static type of the context item

Throws:

XPathException - if a type error is detected

operands

public Iterable<Operand> operands()

Description copied from class: SimpleNodeConstructor

Get the immediate sub-expressions of this expression, with information about the relationship of each expression to its parent expression. Default implementation returns a zero-length array, appropriate for an expression that has no sub-expressions.

Overrides:

operands in class SimpleNodeConstructor

Returns:

an iterator containing the sub-expressions of this expression

copy

public Expression copy()

Copy an expression. This makes a deep copy.

Specified by:

copy in class Expression

Returns:

the copy of the original expression

replaceOperand

public boolean replaceOperand(Expression original,
                     Expression replacement)

Replace one subexpression by a replacement subexpression

Overrides:

replaceOperand in class SimpleNodeConstructor

Parameters:

original - the original subexpression

replacement - the replacement subexpression

Returns:

true if the original subexpression is found

evaluateNodeName

public NodeName evaluateNodeName(XPathContext context)
                          throws XPathException

Description copied from class: SimpleNodeConstructor

Run-time method to compute the name of the node being constructed. This is overridden for nodes that have a name. The default implementation returns -1, which is suitable for unnamed nodes such as comments

Overrides:

evaluateNodeName in class SimpleNodeConstructor

Parameters:

context - the XPath dynamic evaluation context

Returns:

the name pool nameCode identifying the name of the constructed node

Throws:

XPathException - if any failure occurs

processValue

public void processValue(CharSequence value,
                XPathContext context)
                  throws XPathException

Description copied from class: SimpleNodeConstructor

Process the value of the node, to create the new node.

Specified by:

processValue in class SimpleNodeConstructor

Parameters:

value - the string value of the new node

context - the dynamic evaluation context

Throws:

XPathException - if a dynamic error occurs

evaluateItem

public NodeInfo evaluateItem(XPathContext context)
                      throws XPathException

Evaluate as an expression. We rely on the fact that when these instructions are generated by XQuery, there will always be a valueExpression to evaluate the content

Overrides:

evaluateItem in class SimpleNodeConstructor

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

getExpressionCompiler

public ExpressionCompiler getExpressionCompiler()

Return the compiler of the NamespaceConstructor expression

Overrides:

getExpressionCompiler in class Expression

Returns:

the relevant ExpressionCompiler

explain

public void explain(ExpressionPresenter out)

Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.

Specified by:

explain in class Expression

Parameters:

out - the expression presenter used to display the structure