/*******************************************************************************
* Copyright 2014 Analog Devices, Inc.
*
* 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.
********************************************************************************/
package com.analog.lyric.dimple.model.transform;
import net.jcip.annotations.Immutable;
import org.eclipse.jdt.annotation.Nullable;
import com.analog.lyric.dimple.model.transform.VariableEliminator.CostFunction;
import com.analog.lyric.dimple.model.transform.VariableEliminator.VariableCost;
import com.analog.lyric.options.AbstractOptionValueList;
/**
* List of cost functions for use with {@link VariableEliminator}.
* <p>
* This is used in options for solvers that make use of variable elimination (e.g. junction tree).
* <p>
* @since 0.07
* @author Christopher Barber
*/
@Immutable
public class OptionVariableEliminatorCostList extends AbstractOptionValueList<VariableEliminator.CostFunction>
{
private static final long serialVersionUID = 1L;
/**
* An empty list.
*/
public static final OptionVariableEliminatorCostList EMPTY =
new OptionVariableEliminatorCostList(new CostFunction[0]);
/*--------------
* Construction
*/
public OptionVariableEliminatorCostList()
{
super(CostFunction.class);
}
/**
* @param costs
* @since 0.07
*/
public OptionVariableEliminatorCostList(CostFunction ... costs)
{
super(CostFunction.class, costs);
}
/**
* Construct from list of {@link VariableCost}s.
* <p>
* @param costs
* @since 0.07
*/
public OptionVariableEliminatorCostList(VariableCost ... costs)
{
this(VariableCost.toFunctions(costs));
}
public static OptionVariableEliminatorCostList fromObject(@Nullable Object object)
{
if (object == null)
{
return new OptionVariableEliminatorCostList();
}
if ((object instanceof OptionVariableEliminatorCostList))
{
return (OptionVariableEliminatorCostList)object;
}
Class<?> valueClass = object.getClass();
if (valueClass.isArray())
{
Class<?> elementType = valueClass.getComponentType();
if (elementType == CostFunction.class)
{
return new OptionVariableEliminatorCostList((CostFunction[])object);
}
else if (elementType == VariableCost.class)
{
return new OptionVariableEliminatorCostList((VariableCost[])object);
}
else if (!elementType.isPrimitive())
{
Object[] values = (Object[])object;
final int size = values.length;
CostFunction[] costFunctions = new CostFunction[size];
for (int i = 0; i < size; ++i)
{
costFunctions[i] = convertToCostFunction(values[i]);
}
return new OptionVariableEliminatorCostList(costFunctions);
}
}
return new OptionVariableEliminatorCostList(convertToCostFunction(object));
}
private static CostFunction convertToCostFunction(Object value)
{
if (value instanceof VariableCost)
{
return ((VariableCost)value).function();
}
if (value instanceof String)
{
String name = (String)value;
try
{
return VariableCost.valueOf(name).function();
}
catch (IllegalArgumentException ex)
{
// TODO: this is ugly. If we are going to support arbitrary cost functions, then
// we should probably use a ConstructorRegistry to allow lookup of CostFunction constructors.
// If not a VariableCost value, try constructing a class instance:
try
{
return (CostFunction) Class.forName(name).newInstance();
}
catch (Exception ignore)
{
// If that doesn't work, just rethrow the original exception from
// the VariableCost lookup.
throw ex;
}
}
}
return (CostFunction)value;
}
@Override
public boolean isMutable()
{
return false;
}
}