net.sf.saxon.expr.instruct

Class UserFunctionParameter

java.lang.Object

net.sf.saxon.expr.instruct.UserFunctionParameter

All Implemented Interfaces:

Binding, LocalBinding

public class UserFunctionParameter
extends java.lang.Object
implements LocalBinding

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

Constructor Summary

Constructors

Constructor and Description
UserFunctionParameter() Create a UserFunctionParameter

Method Summary

Modifier and Type	Method and Description
void	addReference(VariableReference ref, boolean isLoopingReference) Register a variable reference that refers to the variable bound in this expression
Sequence	evaluateVariable(XPathContext context) Evaluate this function parameter
FunctionStreamability	getFunctionStreamability() If this is the first argument of a streamable stylesheet function, get the streamability category; otherwise return FunctionStreamability.UNCLASSIFIED
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	setFunctionStreamability(FunctionStreamability ability) If this is the first argument of a streamable stylesheet function, set the streamability category
void	setIndexedVariable() Say that the bound value has the potential to be indexed
void	setIndexedVariable(boolean indexed) Indicate that this parameter requires (or does not require) support for indexing
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 LocalBinding

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(VariableReference ref,
                         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:

ref - the variable reference

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

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]

setIndexedVariable

public void setIndexedVariable()

Description copied from interface: LocalBinding

Say that the bound value has the potential to be indexed

Specified by:

setIndexedVariable in interface LocalBinding

isIndexedVariable

public boolean isIndexedVariable()

Ask whether this parameter requires support for indexing

Specified by:

isIndexedVariable in interface LocalBinding

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 Sequence 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

setFunctionStreamability

public void setFunctionStreamability(FunctionStreamability ability)

If this is the first argument of a streamable stylesheet function, set the streamability category

Parameters:

ability - the streamability category

getFunctionStreamability

public FunctionStreamability getFunctionStreamability()

If this is the first argument of a streamable stylesheet function, get the streamability category; otherwise return FunctionStreamability.UNCLASSIFIED

Returns:

the streamability category