/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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.
 */

/**
 * Filters features according their properties.
 * A <cite>filter expression</cite> is a construct used to constraint a feature set to a subset.
 *
 * <p>All filter and expression implementations provided by Apache SIS are thread-safe.
 * They are not necessarily stateless however; for example a filter may remember which
 * warnings have been reported in order to avoid to report the same warning twice.</p>
 *
 * @author  Johann Sorel (Geomatys)
 * @author  Martin Desruisseaux (Geomatys)
 * @version 1.1
 *
 * @see <a href="http://docs.opengeospatial.org/is/09-026r2/09-026r2.html">OGC® Filter Encoding 2.0 Encoding Standard</a>
 *
 * @since 1.1
 * @module
 */
package org.apache.sis.filter;