1 package org.djutils.eval;
2
3 import org.djutils.base.Identifiable;
4 import org.djutils.metadata.MetaData;
5
6 /**
7 * Function.java. Description and implementation of a function that can be registered in and then executed by the Eval evaluator.
8 * <p>
9 * Copyright (c) 2023-2024 Delft University of Technology, Jaffalaan 5, 2628 BX Delft, the Netherlands. All rights reserved. See
10 * for project information <a href="https://djutils.org" target="_blank"> https://djutils.org</a>. The DJUTILS project is
11 * distributed under a three-clause BSD-style license, which can be found at
12 * <a href="https://djutils.org/docs/license.html" target="_blank"> https://djutils.org/docs/license.html</a>.
13 * </p>
14 * @author <a href="https://www.tudelft.nl/pknoppers">Peter Knoppers</a>
15 */
16 public interface Function extends Identifiable
17 {
18 /**
19 * Return the name of the function.
20 * @return String; the name of the function
21 */
22 default String getName()
23 {
24 return getMetaData().getName();
25 }
26 /**
27 * Return a textual description of the function.
28 * @return String; description of the function (may use html tags).
29 */
30 default String getDescription()
31 {
32 return getMetaData().getDescription();
33 }
34
35 /**
36 * Specifies the types of the arguments expected by the function.
37 * @return MetaData; specification of the arguments expected by the function
38 */
39 MetaData getMetaData();
40
41 /**
42 * The function itself.
43 * @param arguments Object[]; the arguments of the function
44 * @return Object; the result of the function (must currently be either some type of DoubleScalar or Boolean).
45 * @throws RuntimeException thrown when the function is unable to produce a result
46 */
47 Object function(Object[] arguments) throws RuntimeException;
48
49 }