DoublePredicate.java revision 607050af5a16c46ae53ff4d2c3f47b4ef694b559 
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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 * @hide 1.8
40 */
41@FunctionalInterface
42public interface DoublePredicate {
43
44    /**
45     * Evaluates this predicate on the given argument.
46     *
47     * @param value the input argument
48     * @return {@code true} if the input argument matches the predicate,
49     * otherwise {@code false}
50     */
51    boolean test(double value);
52
53    /**
54     * Returns a composed predicate that represents a short-circuiting logical
55     * AND of this predicate and another.  When evaluating the composed
56     * predicate, if this predicate is {@code false}, then the {@code other}
57     * predicate is not evaluated.
58     *
59     * <p>Any exceptions thrown during evaluation of either predicate are relayed
60     * to the caller; if evaluation of this predicate throws an exception, the
61     * {@code other} predicate will not be evaluated.
62     *
63     * @param other a predicate that will be logically-ANDed with this
64     *              predicate
65     * @return a composed predicate that represents the short-circuiting logical
66     * AND of this predicate and the {@code other} predicate
67     * @throws NullPointerException if other is null
68     */
69    default DoublePredicate and(DoublePredicate other) {
70        Objects.requireNonNull(other);
71        return (value) -> test(value) && other.test(value);
72    }
73
74    /**
75     * Returns a predicate that represents the logical negation of this
76     * predicate.
77     *
78     * @return a predicate that represents the logical negation of this
79     * predicate
80     */
81    default DoublePredicate negate() {
82        return (value) -> !test(value);
83    }
84
85    /**
86     * Returns a composed predicate that represents a short-circuiting logical
87     * OR of this predicate and another.  When evaluating the composed
88     * predicate, if this predicate is {@code true}, then the {@code other}
89     * predicate is not evaluated.
90     *
91     * <p>Any exceptions thrown during evaluation of either predicate are relayed
92     * to the caller; if evaluation of this predicate throws an exception, the
93     * {@code other} predicate will not be evaluated.
94     *
95     * @param other a predicate that will be logically-ORed with this
96     *              predicate
97     * @return a composed predicate that represents the short-circuiting logical
98     * OR of this predicate and the {@code other} predicate
99     * @throws NullPointerException if other is null
100     */
101    default DoublePredicate or(DoublePredicate other) {
102        Objects.requireNonNull(other);
103        return (value) -> test(value) || other.test(value);
104    }
105}
106