Package net.sf.saxon.expr

Class LocalVariableReference

java.lang.Object

net.sf.saxon.expr.Expression

net.sf.saxon.expr.VariableReference

net.sf.saxon.expr.LocalVariableReference

All Implemented Interfaces:

BindingReference, ExportAgent, Locatable, IdentityComparable, Traceable

public class LocalVariableReference
extends VariableReference

Variable reference: a reference to a local variable. This subclass of VariableReference bypasses the Binding object to get the value directly from the relevant slot in the local stackframe.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	LocalVariableReference.LocalVariableReferenceElaborator	Elaborator for a local variable reference, for example $var.

Field Summary

Fields inherited from class net.sf.saxon.expr.VariableReference

binding, constantValue, staticType

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

EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_COST, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD

Constructor Summary

Constructors

Constructor	Description
LocalVariableReference(LocalBinding binding)	Create a LocalVariableReference bound to a given Binding
LocalVariableReference(StructuredQName name)	Create a local variable reference.

Method Summary

Modifier and Type	Method	Description
Expression	copy(RebindingMap rebindings)	Create a clone copy of this VariableReference
Sequence	evaluateVariable(XPathContext c)	Return the value of the variable
LocalBinding	getBinding()	Get the object bound to the variable
Elaborator	getElaborator()	Make an elaborator for this expression
String	getExpressionName()	Get a name identifying the kind of expression, in terms meaningful to a user.
int	getSlotNumber()	Get the slot number allocated to this local variable
void	setBinding(LocalBinding binding)
void	setSlotNumber(int slotNumber)	Set the slot number for this local variable, that is, its position in the local stack frame

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

addToPathMap, computeCardinality, computeHashCode, computeSpecialProperties, copyFrom, equals, evaluateItem, export, fixup, getDisplayName, getEQName, getImplementationMethod, getIntegerBounds, getIntrinsicDependencies, getItemType, getNetCost, getScopingExpression, getStaticUType, getStreamerName, getVariableName, isFiltered, isFlattened, isInLoop, iterate, optimize, process, recomputeInLoop, refineVariableType, setFiltered, setFlattened, setInLoop, setStaticType, setVariableName, supportsLazyEvaluation, toShortString, toString, typeCheck

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

adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, dispatchTailCall, dynamicError, effectiveBooleanValue, evaluateAsString, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getLocalRetainedStaticContext, getLocation, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isInstruction, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, makeElaborator, markTailFunctionCalls, operandList, operands, operandSparseList, optimizeChildren, prepareForStreaming, resetLocalStaticProperties, restoreParentPointers, setEvaluationMethod, setExtraProperty, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, typeCheckChildren, typeError, unordered, verifyParentPointers, withLocation

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.saxon.trace.Traceable

gatherProperties

Constructor Details

LocalVariableReference

public LocalVariableReference(StructuredQName name)

Create a local variable reference. The binding and slot number will be supplied later

Parameters:

name - the name of the local variable

LocalVariableReference

public LocalVariableReference(LocalBinding binding)

Create a LocalVariableReference bound to a given Binding

Parameters:

binding - the binding (that is, the declaration of this local variable)

Method Details

copy

public Expression copy(RebindingMap rebindings)

Create a clone copy of this VariableReference

Specified by:

copy in class VariableReference

Parameters:

rebindings - a mutable list of (old binding, new binding) pairs that is used to update the bindings held in any local variable references that are copied.

Returns:

the cloned copy

setBinding

public void setBinding(LocalBinding binding)

getBinding

public LocalBinding getBinding()

Description copied from class: VariableReference

Get the object bound to the variable

Overrides:

getBinding in class VariableReference

Returns:

the Binding which declares this variable and associates it with a value

setSlotNumber

public void setSlotNumber(int slotNumber)

Set the slot number for this local variable, that is, its position in the local stack frame

Parameters:

slotNumber - the slot number to be used

getSlotNumber

public int getSlotNumber()

Get the slot number allocated to this local variable

Returns:

the slot number

evaluateVariable

public Sequence evaluateVariable(XPathContext c)
                          throws XPathException

Return the value of the variable

Overrides:

evaluateVariable in class VariableReference

Parameters:

c - the XPath dynamic context

Returns:

the value of the variable

Throws:

XPathException - if any dynamic error occurs while evaluating the variable

getExpressionName

public String getExpressionName()

Get a name identifying the kind of expression, in terms meaningful to a user.

Overrides:

getExpressionName in class VariableReference

Returns:

a name identifying the kind of expression, in terms meaningful to a user. The name will always be in the form of a lexical XML QName, and should match the name used in export() output displaying the expression.

getElaborator

public Elaborator getElaborator()

Make an elaborator for this expression

Overrides:

getElaborator in class Expression

Returns:

a suitable elaborator