/*
* JBoss, Home of Professional Open Source.
* See the COPYRIGHT.txt file distributed with this work for information
* regarding copyright ownership. Some portions may be licensed
* to Red Hat, Inc. under one or more contributor license agreements.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301 USA.
*/
package org.teiid.query.sql.lang;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
import org.teiid.core.TeiidRuntimeException;
import org.teiid.query.sql.symbol.GroupSymbol;
/**
* A GroupContext represents a set of groups in a hierarchy that determines
* resolving order.
*/
public class GroupContext implements Cloneable {
private Collection<GroupSymbol> groups;
private GroupContext parent;
public GroupContext() {
this(null, null);
}
public GroupContext(GroupContext parent, Collection<GroupSymbol> groups) {
this.parent = parent;
if (groups == null) {
this.groups = new LinkedList<GroupSymbol>();
} else {
this.groups = groups;
}
}
public Collection<GroupSymbol> getGroups() {
return this.groups;
}
public void addGroup(GroupSymbol symbol) {
this.groups.add(symbol);
}
public GroupContext getParent() {
return this.parent;
}
/**
* Flattens all contexts to a single list
*
* @return
*/
public List<GroupSymbol> getAllGroups() {
LinkedList<GroupSymbol> result = new LinkedList<GroupSymbol>();
GroupContext root = this;
while (root != null) {
result.addAll(root.getGroups());
root = root.getParent();
}
return result;
}
public Object clone() {
try {
return super.clone();
} catch (CloneNotSupportedException err) {
throw new TeiidRuntimeException(err);
}
}
/**
* @see java.lang.Object#toString()
*/
public String toString() {
String result = groups.toString();
if (parent != null) {
result += "\n" + parent.toString(); //$NON-NLS-1$
}
return result;
}
}