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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
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  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).
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  17  * You should have received a copy of the GNU General Public License version
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  23  * questions.
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  25 package javany.util.function;
  26 
  27 import java.util.Objects;
  28 
  29 /**
  30  * Represents a predicate (boolean-valued function) of one argument.
  31  *
  32  * <p>This is a <a href="package-summary.html">functional interface</a>
  33  * whose functional method is {@link #test(Object)}.
  34  *
  35  * @param <T> the type of the input to the predicate
  36  *
  37  * @since 1.8
  38  */
  39 @FunctionalInterface
  40 public interface Predicate<any T> {
  41 
  42     /**
  43      * Evaluates this predicate on the given argument.
  44      *
  45      * @param t the input argument
  46      * @return {@code true} if the input argument matches the predicate,
  47      * otherwise {@code false}
  48      */
  49     boolean test(T t);
  50 
  51     /**
  52      * Returns a composed predicate that represents a short-circuiting logical
  53      * AND of this predicate and another.  When evaluating the composed
  54      * predicate, if this predicate is {@code false}, then the {@code other}
  55      * predicate is not evaluated.
  56      *
  57      * <p>Any exceptions thrown during evaluation of either predicate are relayed
  58      * to the caller; if evaluation of this predicate throws an exception, the
  59      * {@code other} predicate will not be evaluated.
  60      *
  61      * @param other a predicate that will be logically-ANDed with this
  62      *              predicate
  63      * @return a composed predicate that represents the short-circuiting logical
  64      * AND of this predicate and the {@code other} predicate
  65      * @throws NullPointerException if other is null
  66      */
  67     default Predicate<T> and(Predicate<? super T> other) {
  68         Objects.requireNonNull(other);
  69         return (t) -> test(t) && other.test(t);
  70     }
  71 
  72     /**
  73      * Returns a predicate that represents the logical negation of this
  74      * predicate.
  75      *
  76      * @return a predicate that represents the logical negation of this
  77      * predicate
  78      */
  79     default Predicate<T> negate() {
  80         return (t) -> !test(t);
  81     }
  82 
  83     /**
  84      * Returns a composed predicate that represents a short-circuiting logical
  85      * OR of this predicate and another.  When evaluating the composed
  86      * predicate, if this predicate is {@code true}, then the {@code other}
  87      * predicate is not evaluated.
  88      *
  89      * <p>Any exceptions thrown during evaluation of either predicate are relayed
  90      * to the caller; if evaluation of this predicate throws an exception, the
  91      * {@code other} predicate will not be evaluated.
  92      *
  93      * @param other a predicate that will be logically-ORed with this
  94      *              predicate
  95      * @return a composed predicate that represents the short-circuiting logical
  96      * OR of this predicate and the {@code other} predicate
  97      * @throws NullPointerException if other is null
  98      */
  99     default Predicate<T> or(Predicate<? super T> other) {
 100         Objects.requireNonNull(other);
 101         return (t) -> test(t) || other.test(t);
 102     }
 103 
 104     /**
 105      * Returns a predicate that tests if two arguments are equal according
 106      * to {@link Objects#equals(Object, Object)}.
 107      *
 108      * @param <T> the type of arguments to the predicate
 109      * @param targetRef the object reference with which to compare for equality,
 110      *               which may be {@code null}
 111      * @return a predicate that tests if two arguments are equal according
 112      * to {@link Objects#equals(Object, Object)}
 113      */
 114     static <T> Predicate<T> isEqual(Object targetRef) {
 115         return (null == targetRef)
 116                 ? Objects::isNull
 117                 : object -> targetRef.equals(object);
 118     }
 119 }
--- EOF ---