/*
* Copyright (C) Chaperon. All rights reserved.
* -------------------------------------------------------------------------
* This software is published under the terms of the Apache Software License
* version 1.1, a copy of which has been included with this distribution in
* the LICENSE file.
*/
package net.sourceforge.chaperon.model.extended;
import net.sourceforge.chaperon.model.Violations;
/**
* This class describes a alternation of pattern.
*
* @author <a href="mailto:stephan@apache.org">Stephan Michels</a>
* @version CVS $Id: Choice.java,v 1.4 2004/01/07 08:28:49 benedikta Exp $
*/
public class Choice extends PatternList
{
/**
* Create a pattern for alternation of pattern.
*/
public Choice() {}
public boolean isNullable()
{
boolean nullable = (getPatternCount()==0);
for (int i = 0; i<getPatternCount(); i++)
nullable |= getPattern(i).isNullable();
return nullable;
}
public PatternSet getFirstSet()
{
PatternSet set = new PatternSet();
for (int i = 0; i<getPatternCount(); i++)
set.addPattern(getPattern(i).getFirstSet());
return set;
}
public PatternSet getLastSet()
{
PatternSet set = new PatternSet();
for (int i = 0; i<getPatternCount(); i++)
set.addPattern(getPattern(i).getLastSet());
return set;
}
public void update()
{
for (PatternIterator pattern = getPattern(); pattern.hasNext();)
pattern.next().update();
}
public String toString()
{
StringBuffer buffer = new StringBuffer();
if (getPatternCount()>1)
{
buffer.append("(");
for (int i = 0; i<getPatternCount(); i++)
{
if (i>0)
buffer.append("|");
buffer.append(getPattern(i).toString());
}
buffer.append(")");
}
else if (getPatternCount()==1)
buffer.append(getPattern(0).toString());
return buffer.toString();
}
public String toString(PatternSet previous, PatternSet next)
{
StringBuffer buffer = new StringBuffer();
if (getPatternCount()>1)
{
buffer.append("(");
for (int i = 0; i<getPatternCount(); i++)
{
if (i>0)
buffer.append("|");
buffer.append(getPattern(i).toString(previous, next));
}
buffer.append(")");
}
else if (getPatternCount()==1)
buffer.append(getPattern(0).toString(previous, next));
return buffer.toString();
}
/**
* Create a clone of this pattern.
*
* @return Clone of this pattern.
*
* @throws CloneNotSupportedException If an exception occurs during the cloning.
*/
public Object clone()
{
Choice clone = new Choice();
for (int i = 0; i<getPatternCount(); i++)
clone.addPattern(getPattern(i));
return clone;
}
/**
* Validates this pattern.
*
* @return Return a list of violations, if this pattern isn't valid.
*/
public Violations validate()
{
Violations violations = new Violations();
if (getPatternCount()==0)
violations.addViolation("Choice doesn't contain any elements", getLocation());
for (int i = 0; i<getPatternCount(); i++)
violations.addViolations(getPattern(i).validate());
return violations;
}
}