com.icl.saxon.expr

Class VariableReference


public class VariableReference
extends Expression

Variable reference: a reference to an XSL variable

Field Summary

Fields inherited from class com.icl.saxon.expr.Expression

staticContext

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.

Methods inherited from class com.icl.saxon.expr.Expression

containsReferences, display, enumerate, evaluate, evaluateAsBoolean, evaluateAsNodeSet, evaluateAsNumber, evaluateAsString, getDataType, getDependencies, getStaticContext, indent, isContextDocumentNodeSet, make, outputStringValue, reduce, setStaticContext, simplify, usesCurrent

Constructor Details

VariableReference

public VariableReference(int fingerprint,
                         StaticContext staticContext)
            throws XPathException
Constructor

Parameters:

Method Details

display

public void display(int level)
Diagnostic print of expression structure
Overrides:
display in interface Expression


evaluate

public Value evaluate(Context c)
            throws XPathException
Get the value of this variable in a given context.
Overrides:
evaluate in interface Expression

Parameters:

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


getBinding

public Binding getBinding()
Get the object bound to the variable


getDataType

public int getDataType()
Determine the data type of the expression, if possible
Overrides:
getDataType in interface Expression

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
Overrides:
getDependencies in interface Expression


reduce

public Expression reduce(int dependencies,
                         Context context)
            throws XPathException
Perform a partial evaluation of the expression, by eliminating specified dependencies on the context.
Overrides:
reduce in interface Expression

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.
Overrides:
simplify in interface Expression