2 * Rhynodge - Filter.java - Copyright © 2013 David Roden
4 * This program is free software: you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation, either version 3 of the License, or
7 * (at your option) any later version.
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 package net.pterodactylus.rhynodge;
20 import org.jetbrains.annotations.NotNull;
23 * Defines a filter that runs between {@link Query}s and {@link Merger}s and
24 * can be used to convert a {@link State} into another {@link State}. This can
25 * be used to extract further information from a state.
27 * An example scenario would be a {@link Query} that requests a web site and a
28 * {@link Filter} that extracts content from the web site. That way the same
29 * {@link Query} could be used for multiple {@link Reaction}s without requiring
32 * @author <a href="mailto:bombe@pterodactylus.net">David ‘Bombe’ Roden</a>
34 public interface Filter {
37 * Converts the given state into a different state.
40 * The state to convert
41 * @return The new state
44 State filter(@NotNull State state);