7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package java.util.function;
26
27 /**
28 * An operation upon two operands yielding a result. This is a specialization of
29 * {@code BiFunction} where the operands and the result are all of the same type.
30 *
31 * @param <T> the type of operands to {@code apply} and of the result
32 *
33 * @see BiFunction
34 * @since 1.8
35 */
36 @FunctionalInterface
37 public interface BinaryOperator<T> extends BiFunction<T,T,T> {
38 }
|
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25 package java.util.function;
26
27 import java.util.Objects;
28 import java.util.Comparator;
29
30 /**
31 * An operation upon two operands yielding a result. This is a specialization of
32 * {@code BiFunction} where the operands and the result are all of the same type.
33 *
34 * @param <T> the type of operands to {@code apply} and of the result
35 *
36 * @see BiFunction
37 * @since 1.8
38 */
39 @FunctionalInterface
40 public interface BinaryOperator<T> extends BiFunction<T,T,T> {
41 /**
42 * Constructs a {@link BinaryOperator} which returns the lesser of two elements
43 * according to the specified {@code Comparator}
44 *
45 * @param comparator A {@code Comparator} for comparing the two values
46 * @return a {@code BinaryOperator} which returns the lesser of its operands,
47 * according to the supplied {@code Comparator}
48 */
49 public static<T> BinaryOperator<T> minBy(Comparator<? super T> comparator) {
50 Objects.requireNonNull(comparator);
51 return (a, b) -> comparator.compare(a, b) <= 0 ? a : b;
52 }
53
54 /**
55 * Constructs a {@link BinaryOperator} which returns the greater of two elements
56 * according to the specified {@code Comparator}
57 *
58 * @param comparator A {@code Comparator} for comparing the two values
59 * @return a {@code BinaryOperator} which returns the greater of its operands,
60 * according to the supplied {@code Comparator}
61 */
62 public static<T> BinaryOperator<T> maxBy(Comparator<? super T> comparator) {
63 Objects.requireNonNull(comparator);
64 return (a, b) -> comparator.compare(a, b) >= 0 ? a : b;
65 }
66 }
|