net.sf.saxon.instruct
Class GlobalVariable

java.lang.Object
  net.sf.saxon.expr.Expression
      net.sf.saxon.instruct.Instruction
          net.sf.saxon.instruct.GeneralVariable
              net.sf.saxon.instruct.GlobalVariable

All Implemented Interfaces:

Serializable, SourceLocator, Binding, Container, EvaluableItem, SequenceIterable, TailCallReturner, InstructionInfoProvider

Direct Known Subclasses:

GlobalParam

public class GlobalVariable
extends GeneralVariable
implements Container

A compiled global variable in a stylesheet or query.

See Also:

Serialized Form

Field Summary

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

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

GlobalVariable()
Create a global variable

Method Summary

ValueRepresentation	evaluateVariable(XPathContext context) Evaluate the variable
Executable	getExecutable() Get the executable containing this global variable
int	getHostLanguage() Get the host language for this declaration
InstructionInfo	getInstructionInfo() Get InstructionInfo for this expression
ValueRepresentation	getSelectValue(XPathContext context) Evaluate the variable.
boolean	isGlobal() Is this a global variable?
void	lookForCycles(Stack referees, XQueryFunctionLibrary globalFunctionLibrary) Check for cycles in this variable definition
TailCall	processLeavingTail(XPathContext context) Process the variable declaration
void	setContainsLocals(SlotManager map) The expression that initializes a global variable may itself use local variables.
void	setExecutable(Executable executable) Set the containing executable
void	setHostLanguage(int language) Set the host language for this declaration

Methods inherited from class net.sf.saxon.instruct.GeneralVariable

copy, evaluateItem, explain, getCardinality, getEvaluationMode, getInstructionNameCode, getItemType, getLocalSlotNumber, getRequiredType, getSelectExpression, getSlotNumber, getVariableQName, init, isAssignable, isImplicitlyRequiredParam, isRequiredParam, isTunnelParam, iterate, iterateSubExpressions, optimize, replaceSubExpression, setAssignable, setImplicitlyRequiredParam, setReferenceCount, setRequiredParam, setRequiredType, setSelectExpression, setSlotNumber, setTunnel, setVariableQName, simplify, typeCheck

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

computeCardinality, computeSpecialProperties, createsNewNodes, evaluateAsString, getImplementationMethod, getSourceLocator, isXSLT, process, promote

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

addToPathMap, adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, display, doPromotion, effectiveBooleanValue, explain, findParentOf, getColumnNumber, getContainer, getDependencies, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasLoopingSubexpression, implementsStaticTypeCheck, iterateEvents, markTailFunctionCalls, setContainer, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, toString

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface net.sf.saxon.expr.Container

getLocationProvider, replaceSubExpression

Methods inherited from interface javax.xml.transform.SourceLocator

getColumnNumber, getLineNumber, getPublicId, getSystemId

Constructor Detail

GlobalVariable

public GlobalVariable()

Create a global variable

Method Detail

getExecutable

public Executable getExecutable()

Get the executable containing this global variable

Specified by:

getExecutable in interface Container

Overrides:

getExecutable in class Expression

Returns:

the containing executable

setExecutable

public void setExecutable(Executable executable)

Set the containing executable

Parameters:

executable - the executable that contains this global variable

setHostLanguage

public void setHostLanguage(int language)

Set the host language for this declaration

Parameters:

language - the host language (for example XSLT, XQuery)

getHostLanguage

public int getHostLanguage()

Get the host language for this declaration

Specified by:

getHostLanguage in interface Container

Overrides:

getHostLanguage in class Expression

Returns:

the host language (for example XSLT, XQuery)

setContainsLocals

public void setContainsLocals(SlotManager map)

The expression that initializes a global variable may itself use local variables. In this case a stack frame needs to be allocated while evaluating the global variable

Parameters:

map - The stack frame map for local variables used while evaluating this global variable.

isGlobal

public boolean isGlobal()

Is this a global variable?

Specified by:

isGlobal in interface Binding

Overrides:

isGlobal in class GeneralVariable

Returns:

true (yes, it is a global variable)

lookForCycles

public void lookForCycles(Stack referees,
                          XQueryFunctionLibrary globalFunctionLibrary)
                   throws XPathException

Check for cycles in this variable definition

Parameters:

referees - the calls leading up to this one; it's an error if this variable is on the stack, because that means it calls itself directly or indirectly. The stack may contain variable definitions (GlobalVariable objects) and user-defined functions (UserFunction objects). It will never contain the same object more than once.

globalFunctionLibrary - the library containing all global functions

Throws:

XPathException

processLeavingTail

public TailCall processLeavingTail(XPathContext context)
                            throws XPathException

Process the variable declaration

Specified by:

processLeavingTail in interface TailCallReturner

Specified by:

processLeavingTail in class Instruction

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

getSelectValue

public ValueRepresentation getSelectValue(XPathContext context)
                                   throws XPathException

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

Overrides:

getSelectValue in class GeneralVariable

Parameters:

context - the XPath dynamic context

Returns:

the result of evaluating the variable

Throws:

XPathException

evaluateVariable

public ValueRepresentation evaluateVariable(XPathContext context)
                                     throws XPathException

Evaluate the variable

Specified by:

evaluateVariable in interface Binding

Parameters:

context - the XPath dynamic evaluation context

Returns:

the result of evaluating the variable

Throws:

XPathException

getInstructionInfo

public InstructionInfo getInstructionInfo()

Get InstructionInfo for this expression

Specified by:

getInstructionInfo in interface InstructionInfoProvider

Overrides:

getInstructionInfo in class Instruction