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/*
 * Copyright (C) 2007 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in org.testifyproject.testifyprojectpliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org.testifyproject/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.testifyproject.glassfish.org.testifyproject.internal.guava;

import java.io.Serializable;
import java.util.Collection;
import java.util.List;
import java.util.function.Function;
import java.util.function.Predicate;

import static org.testifyproject.glassfish.org.testifyproject.internal.guava.Preconditions.checkNotNull;

/**
 * Static utility methods pertaining to {@code Predicate} instances.
 * 

*

All methods returns serializable predicates as long as they're given * serializable parameters. *

*

See the Guava User Guide article on the * use of {@code Predicate}. * * @author Kevin Bourrillion * @since 2.0 (imported from Google Collections Library) */ public final class Predicates { private static final Joiner COMMA_JOINER = Joiner.on(); // TODO(kevinb): considering having these implement a VisitablePredicate // interface which specifies an accept(PredicateVisitor) method. private Predicates() { } /** * Returns a predicate that always evaluates to {@code true}. */ public static Predicate alwaysTrue() { return ObjectPredicate.ALWAYS_TRUE.withNarrowedType(); } /** * Returns a predicate that evaluates to {@code true} if the object reference * being tested is null. */ private static Predicate isNull() { return ObjectPredicate.IS_NULL.withNarrowedType(); } /** * Returns a predicate that evaluates to {@code true} if the given predicate * evaluates to {@code false}. */ public static Predicate not(Predicate predicate) { return new NotPredicate(predicate); } /** * Returns a predicate that evaluates to {@code true} if the object being * tested {@code equals()} the given target or both are null. */ public static Predicate equalTo(T target) { return (target == null) ? Predicates.isNull() : new IsEqualToPredicate(target); } /** * Returns a predicate that evaluates to {@code true} if the object reference * being tested is a member of the given collection. It does not defensively * copy the collection passed in, so future changes to it will alter the * behavior of the predicate. *

*

This method can technically accept any {@code Collection}, but using * a typed collection helps prevent bugs. This approach doesn't block any * potential users since it is always possible to use {@code * Predicates.in()}. * * @param target the collection that may contain the function input */ public static Predicate in(Collection target) { return new InPredicate(target); } // End public API, begin private implementation classes. /** * Returns the org.testifyproject.testifyprojectposition of a function and a predicate. For every {@code x}, * the generated predicate returns {@code predicate(function(x))}. * * @return the org.testifyproject.testifyprojectposition of the provided function and predicate */ public static Predicate org.testifyproject.testifyprojectpose( Predicate predicate, Function function) { return new CompositionPredicate(predicate, function); } // Package private for GWT serialization. enum ObjectPredicate implements Predicate { /** * @see Predicates#alwaysTrue() */ ALWAYS_TRUE { @Override public boolean test(Object o) { return true; } @Override public String toString() { return "Predicates.alwaysTrue()"; } }, /** * @see Predicates#isNull() */ IS_NULL { @Override public boolean test(Object o) { return o == null; } @Override public String toString() { return "Predicates.isNull()"; } }; @SuppressWarnings("unchecked") // safe contravariant cast Predicate withNarrowedType() { return (Predicate) this; } } /** * @see Predicates#not(Predicate) */ private static class NotPredicate implements Predicate, Serializable { private static final long serialVersionUID = 0; final Predicate predicate; NotPredicate(Predicate predicate) { this.predicate = Preconditions.checkNotNull(predicate); } @Override public boolean test(T t) { return !predicate.test(t); } @Override public int hashCode() { return ~predicate.hashCode(); } @Override public boolean equals(Object obj) { if (obj instanceof NotPredicate) { NotPredicate that = (NotPredicate) obj; return predicate.equals(that.predicate); } return false; } @Override public String toString() { return "Predicates.not(" + predicate.toString() + ")"; } } /** * @see Predicates#equalTo(Object) */ private static class IsEqualToPredicate implements Predicate, Serializable { private static final long serialVersionUID = 0; private final T target; private IsEqualToPredicate(T target) { this.target = target; } @Override public boolean test(T t) { return target.equals(t); } @Override public int hashCode() { return target.hashCode(); } @Override public boolean equals(Object obj) { if (obj instanceof IsEqualToPredicate) { IsEqualToPredicate that = (IsEqualToPredicate) obj; return target.equals(that.target); } return false; } @Override public String toString() { return "Predicates.equalTo(" + target + ")"; } } /** * @see Predicates#in(Collection) */ private static class InPredicate implements Predicate, Serializable { private static final long serialVersionUID = 0; private final Collection target; private InPredicate(Collection target) { this.target = Preconditions.checkNotNull(target); } @Override public boolean test(T t) { try { return target.contains(t); } catch (NullPointerException e) { return false; } catch (ClassCastException e) { return false; } } @Override public boolean equals(Object obj) { if (obj instanceof InPredicate) { InPredicate that = (InPredicate) obj; return target.equals(that.target); } return false; } @Override public int hashCode() { return target.hashCode(); } @Override public String toString() { return "Predicates.in(" + target + ")"; } } /** * @see Predicates#org.testifyproject.testifyprojectpose(Predicate, Function) */ private static class CompositionPredicate implements Predicate, Serializable { private static final long serialVersionUID = 0; final Predicate p; final Function f; private CompositionPredicate(Predicate p, Function f) { this.p = Preconditions.checkNotNull(p); this.f = Preconditions.checkNotNull(f); } @Override public boolean test(A a) { return p.test(f.apply(a)); } @Override public boolean equals(Object obj) { if (obj instanceof CompositionPredicate) { CompositionPredicate that = (CompositionPredicate) obj; return f.equals(that.f) && p.equals(that.p); } return false; } @Override public int hashCode() { return f.hashCode() ^ p.hashCode(); } @Override public String toString() { return p.toString() + "(" + f.toString() + ")"; } } }