/**********************************************************************
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.memory;
import java.util.Collection;
import java.util.Iterator;
import org.jpox.query.expression.Expression;
import org.jpox.query.expression.ExpressionEvaluator;
import org.jpox.query.symbol.Symbol;
import org.jpox.query.symbol.SymbolTable;
public class SetExpression
{
Iterator it;
public SetExpression(Collection it)
{
this.it = it.iterator();
}
public Object count(Expression expr, ExpressionEvaluator eval)
{
int i=0;
while( it.hasNext())
{
it.next();
i++;
}
return new Long(i);
}
public Object min(Expression paramExpr, ExpressionEvaluator eval, SymbolTable symtbl)
{
int i=0;
Object val = new Float(0);
while( it.hasNext())
{
Symbol s = symtbl.getSymbol("this");
s.setValue(it.next());
Object result = paramExpr.evaluate(eval);
MemoryExpression memexpr = null;
if( i==0)
{
val = result;
}
if( result instanceof Float )
{
memexpr = new FloatExpression((Float) result);
}
else if( result instanceof String )
{
memexpr = new StringExpression((String) result);
}
if (memexpr.lt(val) == Boolean.TRUE)
{
val = result;
}
i++;
}
return val;
}
public Object max(Expression paramExpr, ExpressionEvaluator eval, SymbolTable symtbl)
{
int i=0;
Object val = new Float(0);
while( it.hasNext())
{
Symbol s = symtbl.getSymbol("this");
s.setValue(it.next());
Object result = paramExpr.evaluate(eval);
MemoryExpression memexpr = null;
if( i==0)
{
val = result;
}
if( result instanceof Float )
{
memexpr = new FloatExpression((Float) result);
}
else if( result instanceof String )
{
memexpr = new StringExpression((String) result);
}
if (memexpr.gt(val) == Boolean.TRUE)
{
val = result;
}
i++;
}
return val;
}
public Object sum(Expression paramExpr, ExpressionEvaluator eval, SymbolTable symtbl)
{
int i=0;
Object val = new Float(0);
while( it.hasNext())
{
Symbol s = symtbl.getSymbol("this");
s.setValue(it.next());
Object result = paramExpr.evaluate(eval);
MemoryExpression memexpr = null;
if( result instanceof Float )
{
memexpr = new FloatExpression((Float) result);
}
val = memexpr.add(val);
i++;
}
return val;
}
public Object avg(Expression paramExpr, ExpressionEvaluator eval, SymbolTable symtbl)
{
int i=0;
Object val = new Float(0);
MemoryExpression memexpr = null;
while( it.hasNext())
{
Symbol s = symtbl.getSymbol("this");
s.setValue(it.next());
Object result = paramExpr.evaluate(eval);
if( result instanceof Float )
{
memexpr = new FloatExpression((Float) result);
}
val = memexpr.add(val);
i++;
}
if( val instanceof Float )
{
memexpr = new FloatExpression((Float) val);
}
return memexpr.div(new Float(i));
}
}