/*
* GeoTools - The Open Source Java GIS Toolkit
* http://geotools.org
*
* (C) 2010, Open Source Geospatial Foundation (OSGeo)
*
* 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;
* version 2.1 of the License.
*
* 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.
*/
package org.geotools.filter;
import java.util.List;
import org.opengis.filter.capability.FunctionName;
import org.opengis.filter.expression.Expression;
import org.opengis.filter.expression.Function;
import org.opengis.filter.expression.Literal;
/**
* Factory interface for filter functions.
*
* @author Justin Deoliveira, OpenGeo
*
* @since 2.7
*
* @source $URL: http://svn.osgeo.org/geotools/trunk/modules/library/api/src/main/java/org/geotools/filter/FunctionFactory.java $
*/
public interface FunctionFactory {
/**
* Returns the list of function names the factory provides.
*
* @return A list of function names, possibly empty, never null.
*/
List<FunctionName> getFunctionNames();
/**
* Returns a function with the specified name.
*
* @param name The name of the function
* @param args Variable list of expression arguments for the function.
* @param fallback A fallback literal to use in cases where the function does not exist or
* can not be created. This argument may be {@code null}.
*/
Function function(String name, List<Expression> args, Literal fallback);
}