Package net.sf.saxon.instruct
Class Assign
- java.lang.Object
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- net.sf.saxon.expr.Expression
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- net.sf.saxon.instruct.Instruction
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- net.sf.saxon.instruct.GeneralVariable
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- net.sf.saxon.instruct.Assign
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- All Implemented Interfaces:
java.io.Serializable
,javax.xml.transform.SourceLocator
,LocationProvider
,SaxonLocator
,Binding
,BindingReference
,EvaluableItem
,SequenceIterable
,TailCallReturner
,InstructionInfo
,org.xml.sax.Locator
public class Assign extends GeneralVariable implements BindingReference
saxon:assign element in stylesheet. The saxon:assign element has mandatory attribute name and optional attribute expr. It also allows xsl:extension-element-prefixes etc.- See Also:
- Serialized Form
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Field Summary
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Fields inherited from class net.sf.saxon.instruct.GeneralVariable
evaluationMode, referenceCount, slotNumber, variableQName
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Fields inherited from class net.sf.saxon.expr.Expression
EVALUATE_METHOD, ITERATE_METHOD, locationId, PROCESS_METHOD, staticProperties
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Constructor Summary
Constructors Constructor Description Assign()
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description ValueRepresentation
evaluateVariable(XPathContext context)
Evaluate the variable (method exists only to satisfy the interface)void
explain(ExpressionPresenter out)
Diagnostic print of expression structure.void
fixup(Binding binding)
Fix up this binding reference to a bindingint
getInstructionNameCode()
Get the name of this instruction for diagnostic and tracing purposesint
getIntrinsicDependencies()
Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions.TailCall
processLeavingTail(XPathContext context)
ProcessLeavingTail: called to do the real work of this instruction.Expression
promote(PromotionOffer offer)
Offer promotion for this subexpression.void
setStaticType(SequenceType type, Value constantValue, int properties)
Fix up the static type of this variable reference; optionally, supply a constant value for the variable.-
Methods inherited from class net.sf.saxon.instruct.GeneralVariable
copy, evaluateItem, getCardinality, getEvaluationMode, getItemType, getLocalSlotNumber, getRequiredType, getSelectExpression, getSelectValue, getSlotNumber, getVariableQName, init, isAssignable, isGlobal, isImplicitlyRequiredParam, isRequiredParam, isTunnelParam, iterate, iterateSubExpressions, optimize, promoteInst, replaceSubExpression, setAssignable, setImplicitlyRequiredParam, setReferenceCount, setRequiredParam, setRequiredType, setSelectExpression, setSlotNumber, setTunnel, setVariableQName, simplify, typeCheck
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Methods inherited from class net.sf.saxon.instruct.Instruction
assembleParams, assembleTunnelParams, computeCardinality, computeSpecialProperties, createsNewNodes, dynamicError, evaluateAsString, getConstructType, getImplementationMethod, getSourceLocator, isXSLT, process
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Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, dynamicError, effectiveBooleanValue, evaluatePendingUpdates, explain, findParentOf, getColumnNumber, getColumnNumber, getContainer, getDependencies, getExecutable, getHostLanguage, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, isUpdatingExpression, iterateEvents, markTailFunctionCalls, resetLocalStaticProperties, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toString, typeError
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Method Detail
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setStaticType
public void setStaticType(SequenceType type, Value constantValue, int properties)
Description copied from interface:BindingReference
Fix up the static type of this variable reference; optionally, supply a constant value for the variable. Also supplies other static properties of the expression to which the variable is bound, for example whether it is an ordered node-set.- Specified by:
setStaticType
in interfaceBindingReference
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fixup
public void fixup(Binding binding)
Description copied from interface:BindingReference
Fix up this binding reference to a binding- Specified by:
fixup
in interfaceBindingReference
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getIntrinsicDependencies
public int getIntrinsicDependencies()
Description copied from class:Expression
Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. For example, position() has an intrinsic dependency on the context position, while (position()+1) does not. The default implementation of the method returns 0, indicating "no dependencies".- Overrides:
getIntrinsicDependencies
in classExpression
- Returns:
- a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty
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promote
public Expression promote(PromotionOffer offer) throws XPathException
Offer promotion for this subexpression. This needs careful handling in the case of saxon:assign- Overrides:
promote
in classInstruction
- 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- Returns:
- if the offer is not accepted, return this expression unchanged. Otherwise return the result of rewriting the expression to promote this subexpression
- Throws:
XPathException
- if any error is detected
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getInstructionNameCode
public int getInstructionNameCode()
Get the name of this instruction for diagnostic and tracing purposes- Overrides:
getInstructionNameCode
in classGeneralVariable
- Returns:
- the name of this instruction, as a name pool name code
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processLeavingTail
public TailCall processLeavingTail(XPathContext context) throws XPathException
Description copied from class:Instruction
ProcessLeavingTail: called to do the real work of this instruction. This method must be implemented in each subclass. The results of the instruction are written to the current Receiver, which can be obtained via the Controller.- Specified by:
processLeavingTail
in interfaceTailCallReturner
- Specified by:
processLeavingTail
in classInstruction
- Parameters:
context
- The dynamic context of the transformation, giving access to the current node, the current variables, etc.- Returns:
- null if the instruction has completed execution; or a TailCall indicating a function call or template call that is delegated to the caller, to be made after the stack has been unwound so as to save stack space.
- Throws:
XPathException
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evaluateVariable
public ValueRepresentation evaluateVariable(XPathContext context) throws XPathException
Evaluate the variable (method exists only to satisfy the interface)- Specified by:
evaluateVariable
in interfaceBinding
- Parameters:
context
- the XPath dynamic evaluation context- Returns:
- the result of evaluating the variable
- Throws:
XPathException
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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.- Overrides:
explain
in classGeneralVariable
- Parameters:
out
- the expression presenter used to display the structure
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