DoublePredicate.java revision 4b92e5b21380a5344e5808b17ddffb994f855288 
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25package java.util.function;
26
27import 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
41public 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     */
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     */
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     */
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     */
100    default DoublePredicate or(DoublePredicate other) {
101        Objects.requireNonNull(other);
102        return (value) -> test(value) || other.test(value);
103    }
104}
105