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25 package java.util.function;
26 
27 import java.util.Objects;
28 
29 /**
30  * Represents a predicate (boolean-valued function) of one {@code double}-valued
31  * argument. This is the {@code double}-consuming primitive type specialization
32  * of {@link Predicate}.
33  *
34  * <p>This is a <a href="package-summary.html">functional interface</a>
35  * whose functional method is {@link #test(double)}.
36  *
37  * @see Predicate
38  * @since 1.8
39  */
40 @FunctionalInterface
41 public interface DoublePredicate {
42 
43     /**
44      * Evaluates this predicate on the given argument.
45      *
46      * @param value the input argument
47      * @return {@code true} if the input argument matches the predicate,
48      * otherwise {@code false}
49      */
test(double value)50     boolean test(double value);
51 
52     /**
53      * Returns a composed predicate that represents a short-circuiting logical
54      * AND of this predicate and another.  When evaluating the composed
55      * predicate, if this predicate is {@code false}, then the {@code other}
56      * predicate is not evaluated.
57      *
58      * <p>Any exceptions thrown during evaluation of either predicate are relayed
59      * to the caller; if evaluation of this predicate throws an exception, the
60      * {@code other} predicate will not be evaluated.
61      *
62      * @param other a predicate that will be logically-ANDed with this
63      *              predicate
64      * @return a composed predicate that represents the short-circuiting logical
65      * AND of this predicate and the {@code other} predicate
66      * @throws NullPointerException if other is null
67      */
and(DoublePredicate other)68     default DoublePredicate and(DoublePredicate other) {
69         Objects.requireNonNull(other);
70         return (value) -> test(value) && other.test(value);
71     }
72 
73     /**
74      * Returns a predicate that represents the logical negation of this
75      * predicate.
76      *
77      * @return a predicate that represents the logical negation of this
78      * predicate
79      */
negate()80     default DoublePredicate negate() {
81         return (value) -> !test(value);
82     }
83 
84     /**
85      * Returns a composed predicate that represents a short-circuiting logical
86      * OR of this predicate and another.  When evaluating the composed
87      * predicate, if this predicate is {@code true}, then the {@code other}
88      * predicate is not evaluated.
89      *
90      * <p>Any exceptions thrown during evaluation of either predicate are relayed
91      * to the caller; if evaluation of this predicate throws an exception, the
92      * {@code other} predicate will not be evaluated.
93      *
94      * @param other a predicate that will be logically-ORed with this
95      *              predicate
96      * @return a composed predicate that represents the short-circuiting logical
97      * OR of this predicate and the {@code other} predicate
98      * @throws NullPointerException if other is null
99      */
or(DoublePredicate other)100     default DoublePredicate or(DoublePredicate other) {
101         Objects.requireNonNull(other);
102         return (value) -> test(value) || other.test(value);
103     }
104 }
105