Package net.sf.saxon.expr.instruct
Class GeneralVariable
java.lang.Object
net.sf.saxon.expr.instruct.GeneralVariable
- All Implemented Interfaces:
SourceLocator
,Binding
- Direct Known Subclasses:
GlobalVariable
,LocalParam
,LocalVariable
,WithParam
This class defines common behaviour across xsl:variable, xsl:param, and xsl:with-param;
also saxon:assign
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Field Summary
FieldsModifier and TypeFieldDescriptionprotected int
protected int
(package private) SequenceType
(package private) Expression
protected int
protected StructuredQName
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
addReference
(boolean isLoopingReference) Register a variable reference that refers to the variable bound in this expressionvoid
Check the select expression against the required type.void
copy()
Copy an expression.void
Diagnostic print of expression structure.int
Get the cardinality of the result of this instruction.int
Get the column number of the expressionGet the container in which this expression is located.int
Get the evaluation mode of the variableGet the executable containing this expressionint
Get the name of this instruction (that is xsl:variable, xsl:param etc) for diagnosticsIf the variable is bound to an integer, get the minimum and maximum possible values.int
Get the line number of the expressionint
If this is a local variable held on the local stack frame, return the corresponding slot number.final int
Get the location ID of the expressionGet the LocationProvider allowing location identifiers to be resolved.final String
Get the publicId of the module containing the expression (to satisfy the SourceLocator interface)Get the required type of this variableGet the expression to which this variable is boundgetSelectValue
(XPathContext context) Evaluate the variable.int
Get the slot number allocated to this variableGet the systemId of the module containing the expressiongetSystemId
(long locationId) Get the name of this variablevoid
init
(Expression select, StructuredQName qName) Initialize the properties of the variablefinal boolean
Test whether it is permitted to assign to the variable using the saxon:assign extension element.boolean
isGlobal()
Indicate whether the binding is local or global.final boolean
Ask whether this variable represents a parameter that is implicitly required, because there is no usable default valuefinal boolean
Ask whether this variable represents a required parameterfinal boolean
Ask whether this variable represents a tunnel parameterGet all the XPath expressions associated with this instruction (in XSLT terms, the expression present on attributes of the instruction, as distinct from the child instructions in a sequence construction)void
optimize
(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) boolean
replaceSubExpression
(Expression original, Expression replacement) Replace one subexpression by a replacement subexpressionvoid
setAssignable
(boolean assignable) Indicate whether this variable is assignable using saxon:assignvoid
setContainer
(Container container) Mark a variable as being in a given Container.void
setImplicitlyRequiredParam
(boolean requiredParam) Indicate that this variable represents a parameter that is implicitly required (because there is no usable default value)void
setLocationId
(int id) Set the location ID on an expression.void
setReferenceCount
(int refCount) Set the nominal number of references to this variablevoid
setRequiredParam
(boolean requiredParam) Indicate that this variable represents a required parametervoid
setRequiredType
(SequenceType required) Set the required type of this variablevoid
setSelectExpression
(Expression select) Set the expression to which this variable is boundvoid
setSlotNumber
(int s) Set the slot number of this variablevoid
setTunnel
(boolean tunnel) Indicate whether this variable represents a tunnel parametervoid
Set the name of the variablevoid
simplify
(ExpressionVisitor visitor) Simplify this variablevoid
typeCheck
(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
Methods inherited from interface net.sf.saxon.expr.Binding
evaluateVariable
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Field Details
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select
Expression select -
variableQName
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requiredType
SequenceType requiredType -
slotNumber
protected int slotNumber -
referenceCount
protected int referenceCount -
evaluationMode
protected int evaluationMode
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Constructor Details
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GeneralVariable
public GeneralVariable()Create a general variable
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Method Details
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init
Initialize the properties of the variable- Parameters:
select
- the expression to which the variable is boundqName
- the name of the variable
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setContainer
Mark a variable as being in a given Container. This link is used primarily for diagnostics: the container links to the location map held in the executable.This affects the expression and all its subexpressions. Any subexpressions that are not in the same container are marked with the new container, and this proceeds recursively. However, any subexpression that is already in the correct container is not modified.
- Parameters:
container
- The container of this expression.
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getContainer
Get the container in which this expression is located. This will usually be a top-level construct such as a function or global variable, and XSLT template, or an XQueryExpression. In the case of free-standing XPath expressions it will be the StaticContext object- Returns:
- the expression's container
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setLocationId
public void setLocationId(int id) Set the location ID on an expression.- Parameters:
id
- the location id
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getLocationId
public final int getLocationId()Get the location ID of the expression- Returns:
- a location identifier, which can be turned into real location information by reference to a location provider
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getLineNumber
public int getLineNumber()Get the line number of the expression- Specified by:
getLineNumber
in interfaceSourceLocator
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getColumnNumber
public int getColumnNumber()Get the column number of the expression- Specified by:
getColumnNumber
in interfaceSourceLocator
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getSystemId
Get the systemId of the module containing the expression- Specified by:
getSystemId
in interfaceSourceLocator
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getPublicId
Get the publicId of the module containing the expression (to satisfy the SourceLocator interface)- Specified by:
getPublicId
in interfaceSourceLocator
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getExecutable
Get the executable containing this expression- Returns:
- the containing Executable
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getLocationProvider
Get the LocationProvider allowing location identifiers to be resolved.- Returns:
- the LocationProvider used to turn the location id into real location information
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getSystemId
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setSelectExpression
Set the expression to which this variable is bound- Parameters:
select
- the initializing expression
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getSelectExpression
Get the expression to which this variable is bound- Returns:
- the initializing expression
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setRequiredType
Set the required type of this variable- Parameters:
required
- the required type
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getRequiredType
Get the required type of this variable- Specified by:
getRequiredType
in interfaceBinding
- Returns:
- the required type
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getIntegerBoundsForVariable
If the variable is bound to an integer, get the minimum and maximum possible values. Return null if unknown or not applicable- Specified by:
getIntegerBoundsForVariable
in interfaceBinding
- Returns:
- a pair of integers containing the minimum and maximum values for the integer value; or null if the value is not an integer or the range is unknown
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setAssignable
public void setAssignable(boolean assignable) Indicate whether this variable is assignable using saxon:assign- Parameters:
assignable
- true if this variable is assignable
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setRequiredParam
public void setRequiredParam(boolean requiredParam) Indicate that this variable represents a required parameter- Parameters:
requiredParam
- true if this is a required parameter
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setImplicitlyRequiredParam
public void setImplicitlyRequiredParam(boolean requiredParam) Indicate that this variable represents a parameter that is implicitly required (because there is no usable default value)- Parameters:
requiredParam
- true if this is an implicitly required parameter
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setTunnel
public void setTunnel(boolean tunnel) Indicate whether this variable represents a tunnel parameter- Parameters:
tunnel
- true if this is a tunnel parameter
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setReferenceCount
public void setReferenceCount(int refCount) Set the nominal number of references to this variable- Parameters:
refCount
- the nominal number of references
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getEvaluationMode
public int getEvaluationMode()Get the evaluation mode of the variable- Returns:
- the evaluation mode (a constant in
ExpressionTool
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isAssignable
public final boolean isAssignable()Test whether it is permitted to assign to the variable using the saxon:assign extension element. This will only be true if the extra attribute saxon:assignable="yes" is present.- Specified by:
isAssignable
in interfaceBinding
- Returns:
- true if the binding is assignable
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getCardinality
public int getCardinality()Get the cardinality of the result of this instruction. An xsl:variable instruction returns nothing, so the type is empty.- Returns:
- the empty cardinality.
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isGlobal
public boolean isGlobal()Description copied from interface:Binding
Indicate whether the binding is local or global. A global binding is one that has a fixed value for the life of a query or transformation; any other binding is local. -
getLocalSlotNumber
public int getLocalSlotNumber()If this is a local variable held on the local stack frame, return the corresponding slot number. In other cases, return -1.- Specified by:
getLocalSlotNumber
in interfaceBinding
- Returns:
- the slot number on the local stack frame
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isRequiredParam
public final boolean isRequiredParam()Ask whether this variable represents a required parameter- Returns:
- true if this is a required parameter
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isImplicitlyRequiredParam
public final boolean isImplicitlyRequiredParam()Ask whether this variable represents a parameter that is implicitly required, because there is no usable default value- Returns:
- true if this variable is an implicitly required parameter
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isTunnelParam
public final boolean isTunnelParam()Ask whether this variable represents a tunnel parameter- Returns:
- true if this is a tunnel parameter
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getInstructionNameCode
public int getInstructionNameCode()Get the name of this instruction (that is xsl:variable, xsl:param etc) for diagnostics- Returns:
- the name of this instruction, as a name pool name code
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simplify
Simplify this variable- Parameters:
visitor
- an expression- Throws:
XPathException
- if a failure occurs
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typeCheck
public void typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException - Throws:
XPathException
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optimize
public void optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException - Throws:
XPathException
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computeEvaluationMode
public void computeEvaluationMode() -
copy
Copy an expression. This makes a deep copy.- Returns:
- the copy of the original expression
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addReference
public void addReference(boolean isLoopingReference) Description copied from interface:Binding
Register a variable reference that refers to the variable bound in this expression- Specified by:
addReference
in interfaceBinding
- Parameters:
isLoopingReference
- - true if the reference occurs within a loop, such as the predicate of a filter expression
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checkAgainstRequiredType
Check the select expression against the required type.- Parameters:
visitor
- an expression visitor- Throws:
XPathException
- if the check fails
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getSelectValue
Evaluate the variable. That is, get the value of the select expression if present or the content of the element otherwise, either as a tree or as a sequence- Parameters:
context
- the XPath dynamic context- Returns:
- the result of evaluating the variable
- Throws:
XPathException
- if evaluation of the select expression fails with a dynamic error
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iterateSubExpressions
Get all the XPath expressions associated with this instruction (in XSLT terms, the expression present on attributes of the instruction, as distinct from the child instructions in a sequence construction)- Returns:
- an iterator over all the contained expressions (in practice, the select expression)
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replaceSubExpression
Replace one subexpression by a replacement subexpression- Parameters:
original
- the original subexpressionreplacement
- the replacement subexpression- Returns:
- true if the original subexpression is found
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explain
Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.- Parameters:
out
- the object used to present the output
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getSlotNumber
public int getSlotNumber()Get the slot number allocated to this variable- Returns:
- the slot number, that is the position allocated to the variable on its stack frame
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setSlotNumber
public void setSlotNumber(int s) Set the slot number of this variable- Parameters:
s
- the slot number, that is, the position allocated to this variable on its stack frame
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setVariableQName
Set the name of the variable- Parameters:
s
- the name of the variable (a QName)
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getVariableQName
Get the name of this variable- Specified by:
getVariableQName
in interfaceBinding
- Returns:
- the name of this variable (a QName)
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