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1   /*
2    * Licensed to the Apache Software Foundation (ASF) under one or more
3    * contributor license agreements.  See the NOTICE file distributed with
4    * this work for additional information regarding copyright ownership.
5    * The ASF licenses this file to You under the Apache License, Version 2.0
6    * (the "License"); you may not use this file except in compliance with
7    * the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   * Unless required by applicable law or agreed to in writing, software
12   * distributed under the License is distributed on an "AS IS" BASIS,
13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   * See the License for the specific language governing permissions and
15   * limitations under the License.
16   */
17  package org.apache.commons.math4.legacy.core;
18  
19  import org.apache.commons.math4.legacy.exception.MathArithmeticException;
20  import org.apache.commons.math4.legacy.exception.NullArgumentException;
21  
22  
23  /**
24   * Interface representing <a href="http://mathworld.wolfram.com/Field.html">field</a> elements.
25   * @param <T> the type of the field elements
26   * @see Field
27   * @since 2.0
28   */
29  public interface FieldElement<T> {
30  
31      /** Compute this + a.
32       * @param a element to add
33       * @return a new element representing this + a
34       * @throws NullArgumentException if {@code a} is {@code null}.
35       */
36      T add(T a) throws NullArgumentException;
37  
38      /** Compute this - a.
39       * @param a element to subtract
40       * @return a new element representing this - a
41       * @throws NullArgumentException if {@code a} is {@code null}.
42       */
43      T subtract(T a) throws NullArgumentException;
44  
45      /**
46       * Returns the additive inverse of {@code this} element.
47       * @return the opposite of {@code this}.
48       */
49      T negate();
50  
51      /** Compute n &times; this. Multiplication by an integer number is defined
52       * as the following sum:
53       * <p>n &times; this = &sum;<sub>i=1</sub><sup>n</sup> this.
54       * @param n Number of times {@code this} must be added to itself.
55       * @return A new element representing n &times; this.
56       */
57      T multiply(int n);
58  
59      /** Compute this &times; a.
60       * @param a element to multiply
61       * @return a new element representing this &times; a
62       * @throws NullArgumentException if {@code a} is {@code null}.
63       */
64      T multiply(T a) throws NullArgumentException;
65  
66      /** Compute this &divide; a.
67       * @param a element to divide by
68       * @return a new element representing this &divide; a
69       * @throws NullArgumentException if {@code a} is {@code null}.
70       * @throws MathArithmeticException if {@code a} is zero
71       */
72      T divide(T a) throws NullArgumentException, MathArithmeticException;
73  
74      /**
75       * Returns the multiplicative inverse of {@code this} element.
76       * @return the inverse of {@code this}.
77       * @throws MathArithmeticException if {@code this} is zero
78       */
79      T reciprocal() throws MathArithmeticException;
80  
81      /** Get the {@link Field} to which the instance belongs.
82       * @return {@link Field} to which the instance belongs
83       */
84      Field<T> getField();
85  }