com.icl.saxon.expr

Class VariableReference

public class VariableReference extends Expression

Variable reference: a reference to an XSL variable

Field Summary
Binding	binding
int	fingerprint

Constructor Summary
	VariableReference(int fingerprint, StaticContext staticContext) Constructor

Method Summary
void	display(int level) Diagnostic print of expression structure
Value	evaluate(Context c) Get the value of this variable in a given context.
Binding	getBinding() Get the object bound to the variable
int	getDataType() Determine the data type of the expression, if possible
int	getDependencies() Determine which aspects of the context the expression depends on.
Expression	reduce(int dependencies, Context context) Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
Expression	simplify() Simplify the expression.

Field Detail

binding

Binding binding

fingerprint

int fingerprint

Constructor Detail

VariableReference

public VariableReference(int fingerprint, StaticContext staticContext)

Constructor

Parameters: name the variable name (as a Name object)

Method Detail

display

public void display(int level)

Diagnostic print of expression structure

evaluate

public Value evaluate(Context c)

Get the value of this variable in a given context.

Parameters: context the Context which contains the relevant variable bindings

Returns: the value of the variable, if it is defined

UNKNOWN: XPathException if the variable is undefined

getBinding

public Binding getBinding()

Get the object bound to the variable

getDataType

public int getDataType()

Determine the data type of the expression, if possible

Returns: the type of the variable, if this can be determined statically; otherwise Value.ANY (meaning not known in advance)

getDependencies

public int getDependencies()

Determine which aspects of the context the expression depends on. The result is a bitwise-or'ed value composed from constants such as Context.VARIABLES and Context.CURRENT_NODE

reduce

public Expression reduce(int dependencies, Context context)

Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.

Parameters: dependencies The dependencies to be removed context The context to be used for the partial evaluation

Returns: a new expression that does not have any of the specified dependencies

simplify

public Expression simplify()

Simplify the expression. If the variable has a fixed value, the variable reference will be replaced with that value.