net.sf.saxon.expr.instruct
Class UserFunctionParameter

java.lang.Object
  net.sf.saxon.expr.instruct.UserFunctionParameter

All Implemented Interfaces:

Serializable, Binding

public class UserFunctionParameter
extends Object
implements Binding, Serializable

Run-time object representing a formal argument to a user-defined function

See Also:

Serialized Form

Constructor Summary

UserFunctionParameter()
Create a UserFunctionParameter

Method Summary

void	addReference(boolean isLoopingReference) Register a variable reference that refers to the variable bound in this expression
ValueRepresentation	evaluateVariable(XPathContext context) Evaluate this function parameter
IntegerValue[]	getIntegerBoundsForVariable() If the variable is bound to an integer, get the minimum and maximum possible values.
int	getLocalSlotNumber() If this is a local variable held on the local stack frame, return the corresponding slot number.
int	getReferenceCount() Get the (nominal) number of references within the function body to this parameter, where a reference inside a loop is counted as multiple references
SequenceType	getRequiredType() Get the required type of this function parameter
StructuredQName	getVariableQName() Get the name of this parameter
boolean	isAssignable() 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.
boolean	isIndexedVariable() Ask whether this parameter requires support for indexing
void	setIndexedVariable(boolean indexed) Indicate that this parameter requires (or does not require) support for indexing
void	setReferenceCount(int count) Set the (nominal) number of references within the function body to this parameter, where a reference inside a loop is counted as multiple references
void	setRequiredType(SequenceType type) Set the required type of this function parameter
void	setSlotNumber(int slot) Set the slot number to be used by this parameter
void	setVariableQName(StructuredQName name) Set the name of this parameter

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

UserFunctionParameter

public UserFunctionParameter()

Create a UserFunctionParameter

Method Detail

isGlobal

public final boolean isGlobal()

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.

Specified by:

isGlobal in interface Binding

Returns:

false (always)

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 for an XSLT global variable where the extra attribute saxon:assignable="yes" is present.

Specified by:

isAssignable in interface Binding

Returns:

false (always)

setSlotNumber

public void setSlotNumber(int slot)

Set the slot number to be used by this parameter

Parameters:

slot - the slot number, that is, the position of the parameter value within the local stack frame

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 interface Binding

Returns:

the slot number, indicating the position of the parameter on the local stack frame

setRequiredType

public void setRequiredType(SequenceType type)

Set the required type of this function parameter

Parameters:

type - the declared type of the parameter

getRequiredType

public SequenceType getRequiredType()

Get the required type of this function parameter

Specified by:

getRequiredType in interface Binding

Returns:

the declared type of the parameter

getIntegerBoundsForVariable

public IntegerValue[] 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 interface Binding

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

setVariableQName

public void setVariableQName(StructuredQName name)

Set the name of this parameter

Parameters:

name - the name of the parameter

getVariableQName

public StructuredQName getVariableQName()

Get the name of this parameter

Specified by:

getVariableQName in interface Binding

Returns:

the name of this parameter

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 interface Binding

Parameters:

isLoopingReference - - true if the reference occurs within a loop, such as the predicate of a filter expression

setReferenceCount

public void setReferenceCount(int count)

Set the (nominal) number of references within the function body to this parameter, where a reference inside a loop is counted as multiple references

Parameters:

count - the nominal number of references

getReferenceCount

public int getReferenceCount()

Get the (nominal) number of references within the function body to this parameter, where a reference inside a loop is counted as multiple references

Returns:

the nominal number of references

setIndexedVariable

public void setIndexedVariable(boolean indexed)

Indicate that this parameter requires (or does not require) support for indexing

Parameters:

indexed - true if support for indexing is required. This will be set if the parameter is used in a filter expression such as $param[@a = 17]

isIndexedVariable

public boolean isIndexedVariable()

Ask whether this parameter requires support for indexing

Returns:

true if support for indexing is required. This will be set if the parameter is used in a filter expression such as $param[@a = 17]

evaluateVariable

public ValueRepresentation evaluateVariable(XPathContext context)
                                     throws XPathException

Evaluate this function parameter

Specified by:

evaluateVariable in interface Binding

Parameters:

context - the XPath dynamic context

Returns:

the value of the parameter

Throws:

XPathException - if an error occurs