Package net.sf.saxon.expr.instruct
Class NamespaceConstructor
- java.lang.Object
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- net.sf.saxon.expr.Expression
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- net.sf.saxon.expr.instruct.Instruction
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- net.sf.saxon.expr.instruct.SimpleNodeConstructor
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- net.sf.saxon.expr.instruct.NamespaceConstructor
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- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,LocationProvider
,SaxonLocator
,TailCallReturner
,InstructionInfo
,org.xml.sax.Locator
public class NamespaceConstructor extends SimpleNodeConstructor
A namespace constructor instruction. (xsl:namespace in XSLT 2.0, or namespace{}{} in XQuery 1.1)- See Also:
- Serialized Form
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Field Summary
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Fields inherited from class net.sf.saxon.expr.instruct.SimpleNodeConstructor
select
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Fields inherited from class net.sf.saxon.expr.Expression
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD
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Constructor Summary
Constructors Constructor Description NamespaceConstructor(Expression name)
Create an xsl:namespace instruction for dynamic construction of namespace nodes
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method 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.int
getInstructionNameCode()
Set the name of this instruction for diagnostic and tracing purposesItemType
getItemType(TypeHierarchy th)
Get the item type of the items returned by evaluating this instructionExpression
getNameExpression()
Get the expression that defines the namespace node's namejava.util.Iterator<Expression>
iterateSubExpressions()
Get the immediate sub-expressions of this expression.void
localTypeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType)
Method to perform type-checking specific to the kind of instructionvoid
processValue(java.lang.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
replaceSubExpression(Expression original, Expression replacement)
Replace one subexpression by a replacement subexpressionExpression
simplify(ExpressionVisitor visitor)
Simplify an expression.-
Methods inherited from class net.sf.saxon.expr.instruct.SimpleNodeConstructor
checkContent, computeCardinality, computeSpecialProperties, createsNewNodes, getContentExpression, iterate, optimize, processLeavingTail, setSelect, typeCheck
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Methods inherited from class net.sf.saxon.expr.instruct.Instruction
assembleParams, assembleTunnelParams, dynamicError, evaluateAsString, getConstructType, getExpressionName, getImplementationMethod, getInstructionName, getIteratorFromProcessMethod, getSourceLocator, isXSLT, process, promote
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Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, getColumnNumber, getColumnNumber, getContainer, getDependencies, getEvaluationMethod, getExecutable, getHostLanguage, getIntegerBounds, getIntrinsicDependencies, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, resetLocalStaticProperties, setContainer, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toString, typeError
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Constructor Detail
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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)
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Method Detail
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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)
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getInstructionNameCode
public int getInstructionNameCode()
Set the name of this instruction for diagnostic and tracing purposes- Overrides:
getInstructionNameCode
in classInstruction
- Returns:
- a code identifying the instruction: typically but not always the fingerprint of a name in the XSLT namespace
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simplify
public Expression simplify(ExpressionVisitor visitor) throws XPathException
Description copied from class:Instruction
Simplify an expression. This performs any static optimization (by rewriting the expression as a different expression). The default implementation does nothing.- Overrides:
simplify
in classSimpleNodeConstructor
- Parameters:
visitor
- an expression visitor- Returns:
- the simplified expression
- Throws:
XPathException
- if an error is discovered during expression rewriting
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getItemType
public ItemType getItemType(TypeHierarchy th)
Description copied from class:Instruction
Get the item type of the items returned by evaluating this instruction- Overrides:
getItemType
in classInstruction
- Parameters:
th
- the type hierarchy cache- Returns:
- the static item type of the instruction
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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 classExpression
- 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).
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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 classSimpleNodeConstructor
- 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
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localTypeCheck
public void localTypeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
Description copied from class:SimpleNodeConstructor
Method to perform type-checking specific to the kind of instruction- Specified by:
localTypeCheck
in classSimpleNodeConstructor
- Parameters:
visitor
- an expression visitorcontextItemType
- the static type of the context item- Throws:
XPathException
- if a type error is detected
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iterateSubExpressions
public java.util.Iterator<Expression> iterateSubExpressions()
Description copied from class:Expression
Get the immediate sub-expressions of this expression. Default implementation returns a zero-length array, appropriate for an expression that has no sub-expressions.- Overrides:
iterateSubExpressions
in classSimpleNodeConstructor
- Returns:
- an iterator containing the sub-expressions of this expression
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copy
public Expression copy()
Copy an expression. This makes a deep copy.- Specified by:
copy
in classExpression
- Returns:
- the copy of the original expression
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replaceSubExpression
public boolean replaceSubExpression(Expression original, Expression replacement)
Replace one subexpression by a replacement subexpression- Overrides:
replaceSubExpression
in classSimpleNodeConstructor
- Parameters:
original
- the original subexpressionreplacement
- the replacement subexpression- Returns:
- true if the original subexpression is found
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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 classSimpleNodeConstructor
- 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
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processValue
public void processValue(java.lang.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 classSimpleNodeConstructor
- Parameters:
value
- the string value of the new nodecontext
- the dynamic evaluation context- Throws:
XPathException
- if a dynamic error occurs
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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 classSimpleNodeConstructor
- 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
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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 classExpression
- Parameters:
out
- the expression presenter used to display the structure
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