csheets.core.formula.util
Class CircularReferenceFinder

java.lang.Object
  csheets.core.formula.util.AbstractExpressionVisitor
      csheets.core.formula.util.CircularReferenceFinder

All Implemented Interfaces:

ExpressionVisitor

public class CircularReferenceFinder
extends AbstractExpressionVisitor

An expression visitor that looks for circular references in a formula, i.e. a reference back to the cell in the formula of a cell that precedes it.

Author:

Einar Pehrson

Constructor Summary

CircularReferenceFinder()
Creates a new circular reference finder.

Method Summary

void	check(Formula formula) Checks if the given formula has any circular references.
Object	visitReference(Reference reference) Checks if the given reference causes a circular reference.

Methods inherited from class csheets.core.formula.util.AbstractExpressionVisitor

visitBinaryOperation, visitFunctionCall, visitLiteral, visitUnaryOperation

Methods inherited from class java.lang.Object

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

Constructor Detail

CircularReferenceFinder

public CircularReferenceFinder()

Creates a new circular reference finder.

Method Detail

check

public void check(Formula formula)
           throws CircularReferenceException

Checks if the given formula has any circular references.

Throws:

CircularReferenceException - if the formula contains any circular references

visitReference

public Object visitReference(Reference reference)
                      throws CircularReferenceException,
                             ExpressionVisitorException

Checks if the given reference causes a circular reference.

Specified by:

visitReference in interface ExpressionVisitor

Overrides:

visitReference in class AbstractExpressionVisitor

Parameters:

reference - the reference to visit

Returns:

an arbitrary object

Throws:

CircularReferenceException - if the given reference causes a circular reference

ExpressionVisitorException