/**********************************************************************
Copyright (c) 2008 Erik Bengtson and others. All rights reserved.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
Contributors:
...
**********************************************************************/
package org.jpox.query.evaluator;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import org.jpox.ClassLoaderResolver;
import org.jpox.query.evaluator.memory.InMemoryExpressionEvaluator;
import org.jpox.query.expression.Expression;
import org.jpox.query.symbol.Symbol;
import org.jpox.query.symbol.SymbolTable;
import org.jpox.util.Imports;
public class Evaluator
{
// TODO Remove HARDCODED "this". Should be alias of some name
public Collection evaluate(SymbolTable symtbl, Expression expr, Imports imports, ClassLoaderResolver clr)
{
Symbol symThis = symtbl.getSymbol("this");
Collection candidates = (Collection) symThis.getValue();
Iterator it = candidates.iterator();
Collection result = new HashSet();
while(it.hasNext())
{
symThis.setValue(it.next());
if( expr.evaluate(new InMemoryExpressionEvaluator(symtbl, imports, clr)) == Boolean.TRUE )
{
result.add(symThis.getValue());
}
}
return result;
}
}