--- /dev/null 2011-08-08 08:40:49.685541141 -0700
+++ new/src/share/classes/java/util/functions/Predicates.java 2011-08-09 10:55:28.000000000 -0700
@@ -0,0 +1,648 @@
+/*
+ * Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+package java.util.functions;
+
+import java.lang.reflect.Array;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.List;
+import java.util.Objects;
+
+/**
+ * Static utility methods pertaining to {@code Predicate} instances.
+ *
+ *
All of the returned predicates are serializable if given serializable
+ * parameters.
+ */
+public final class Predicates {
+
+ /**
+ * a predicate that evaluates to {@code true} if the reference
+ * being tested is {@code null}.
+ */
+ public static final Predicate IS_NULL = #{Object t -> t == null};
+
+ /**
+ * a predicate that evaluates to {@code true} if the reference
+ * being tested is not {@code null}.
+ */
+ public static final Predicate NON_NULL = #{Object t -> t != null};
+
+ /**
+ * a predicate who's result is always {@code false}.
+ */
+ public static final Predicate FALSE = #{Object t -> false};
+
+
+ /**
+ * a predicate who's result is always {@code true}.
+ */
+ public static final Predicate TRUE = #{Object t -> true};
+
+ /**
+ * singleton utils
+ */
+ private Predicates() {
+ throw new AssertionError("No instances!");
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if the reference
+ * being tested is {@code null}.
+ *
+ * @return a predicate that evaluates to {@code true} if the reference
+ * being tested is {@code null}
+ */
+ public static Predicate isNull() {
+ return (Predicate) IS_NULL;
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if the reference
+ * being tested is non-{@code null}.
+ *
+ * @return a predicate that evaluates to {@code true} if the reference
+ * being tested is is non-{@code null}
+ */
+ public static Predicate nonNull() {
+ return (Predicate) NON_NULL;
+ }
+
+ /**
+ * Returns a predicate who's result is always {@code false}.
+ *
+ * @return a predicate who's result is always {@code false}.
+ */
+ public static Predicate alwaysFalse() {
+ return (Predicate) FALSE;
+ }
+
+ /**
+ * Returns a predicate who's result is always {@code true}.
+ *
+ * @return a predicate who's result is always {@code true}.
+ */
+ public static Predicate alwaysTrue() {
+ return (Predicate) TRUE;
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if the object being
+ * tested is an instance of the provided class. If the object being tested
+ * is {@code null} this predicate evaluates to {@code false}.
+ *
+ * @param clazz The target class to be matched by the predicate.
+ * @return a predicate that evaluates to {@code true} if the object being
+ * tested is an instance of the provided class
+ */
+ public static Predicate instanceOf(Class> clazz) {
+ return #{Object o -> clazz.isInstance(o)};
+ }
+
+ /**
+ * Returns a predicate that who's result is {@code target == object}.
+ *
+ * @param the type of predicate values.
+ * @param t The target value to be compared for identity equality.
+ * @return a predicate that who's result is {@code target == object}
+ */
+ public static Predicate isSame(T target) {
+ return #{T t -> t == target};
+ }
+
+ /**
+ * Returns a predicate who's result matches
+ * {@code Objects.equals(target, t)}.
+ *
+ * @param the type of predicate values.
+ * @param t The target value to be compared for equality.
+ * @return a predicate who's result matches {@code Objects.equals(target, t)}
+ */
+ public static Predicate isEqual(T target) {
+ if (null == target)
+ return Predicates.isNull();
+ else
+ return #{T t -> target.equals(t)};
+ }
+
+ /**
+ * Creates a predicate that evaluates to {@code true} if the tested object
+ * is a member of the provided collection. The collection is not defensively
+ * copied so changes to it will alter the behavior of the predicate.
+ *
+ * @param Type of predicate values.
+ * @param target the collection against which objects will be tested.
+ * @return a predicate that evaluates to {@code true} if the tested object
+ * is a member of the provided collection. The collection is not defensively
+ * copied so changes to it will alter the behavior of the predicate.
+ */
+ public static Predicate contains(Collection extends T> target) {
+ return #{T t -> target.contains(t)};
+ }
+
+ /**
+ * Creates a predicate that is a composition of a mapper and a predicate.
+ * The returned predicate's result is {@code predicate.eval(mapper.map(t))}.
+ *
+ * @return the composition of the provided mapper and predicate
+ */
+ public static Predicate compose(
+ Predicate predicate, Mapper mapper) {
+ return #{T t -> predicate.eval(mapper.map(t))};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if the provided
+ * predicate evaluates to {@code false}
+ *
+ * @param the type of values evaluated by the predicate.
+ * @param predicate The predicate to be evaluated.
+ * @return A predicate who's result is the logical inverse of the provided
+ * predicate.
+ */
+ public static > Predicate negate(
+ P predicate) {
+ return #{T t -> !predicate.eval(t)};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if all of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will terminate upon the first
+ * {@code false} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param first initial component predicate to be evaluated.
+ * @param second additional component predicate to be evaluated.
+ * @return A predicate who's result is {@code true} iff all component
+ * predicates are {@code true}.
+ */
+ public static > Predicate and(
+ Predicate first, P second) {
+ if((null != first) && (first == second)) {
+ return (Predicate) first;
+ }
+
+ Objects.requireNonNull(first);
+ Objects.requireNonNull(second);
+
+ return #{T t -> first.eval(t) && second.eval(t)};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if all of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end upon the first
+ * {@code false} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated.
+ * @return A predicate who's result is {@code true} iff all component
+ * predicates are {@code true}.
+ */
+ public static > Predicate and(
+ Iterable components) {
+ List
predicates = safeCopyOf(components);
+ if(predicates.isEmpty()) {
+ throw new IllegalArgumentException("no predicates");
+ }
+
+ return #{T t ->
+ for(P predicate : predicates) {
+ if(!predicate.eval(t)) {
+ return false;
+ }
+ }
+ return true;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if all of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end upon the first
+ * {@code false} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated.
+ * @return A predicate who's result is {@code true} iff all component
+ * predicates are {@code true}.
+ */
+ static > Predicate and(
+ P first, Iterable components) {
+ List
predicates = safeCopyOf(first, components);
+
+ return #{T t ->
+ for(P predicate : predicates) {
+ if(!predicate.eval(t)) {
+ return false;
+ }
+ }
+ return true;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if all of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end upon the first
+ * {@code false} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return A predicate who's result is {@code true} iff all component
+ * predicates are {@code true}.
+ */
+ @SafeVarargs
+ public static > Predicate and(
+ P... components) {
+ P[] predicates = safeCopyOf(components);
+ if(0 == predicates.length) {
+ throw new IllegalArgumentException("no predicates");
+ }
+
+ return #{T t ->
+ for(P predicate : predicates) {
+ if(!predicate.eval(t)) {
+ return false;
+ }
+ }
+ return true;};
+ }
+ /**
+ * Returns a predicate that evaluates to {@code true} if all of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end upon the first
+ * {@code false} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param first first predicate to be evaluated.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return A predicate who's result is {@code true} iff all component
+ * predicates are {@code true}.
+ */
+ @SafeVarargs
+ static > Predicate and(
+ P first, P... components) {
+ P[] predicates = safeCopyOf(first, components);
+ if(0 == predicates.length) {
+ throw new IllegalArgumentException("no predicates");
+ }
+
+ return #{T t ->
+ for(P predicate : predicates) {
+ if(!predicate.eval(t)) {
+ return false;
+ }
+ }
+ return true;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if any of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end upon the first
+ * {@code true} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param first initial component predicate to be evaluated.
+ * @param second additional component predicate to be evaluated.
+ * @return A predicate who's result is {@code true} if any component
+ * predicate's result is {@code true}.
+ */
+ public static > Predicate or(
+ Predicate first, P second) {
+ if((null != first) && (first == second)) {
+ return first;
+ }
+
+ Objects.requireNonNull(first);
+ Objects.requireNonNull(second);
+
+ return #{T t -> first.eval(t) || second.eval(t)};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if any of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end upon the first
+ * {@code true} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return A predicate who's result is {@code true} if any component
+ * predicate's result is {@code true}.
+ */
+ public static > Predicate or(
+ Iterable components) {
+ List
predicates = safeCopyOf(components);
+ if(predicates.isEmpty()) {
+ throw new IllegalArgumentException("no predicates");
+ }
+
+ return #{T t ->
+ for(P predicate : predicates) {
+ if(predicate.eval(t)) {
+ return true;
+ }
+ }
+ return false;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if any of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end upon the first
+ * {@code true} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return A predicate who's result is {@code true} if any component
+ * predicate's result is {@code true}.
+ */
+ static > Predicate or(
+ P first, Iterable components) {
+ List
predicates = safeCopyOf(first, components);
+
+ return #{T t ->
+ for(P predicate : predicates) {
+ if(predicate.eval(t)) {
+ return true;
+ }
+ }
+ return false;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if any of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will terminate upon the first
+ * {@code true} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return A predicate who's result is {@code true} if any component
+ * predicate's result is {@code true}.
+ */
+ @SafeVarargs
+ public static > Predicate or(
+ P... components) {
+ P[] predicates = safeCopyOf(components);
+ if(0 == predicates.length) {
+ throw new IllegalArgumentException("no predicates");
+ }
+
+ return #{T t ->
+ for(P predicate : predicates) {
+ if(predicate.eval(t)) {
+ return true;
+ }
+ }
+ return false;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if any of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will terminate upon the first
+ * {@code true} predicate.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return A predicate who's result is {@code true} if any component
+ * predicate's result is {@code true}.
+ */
+ @SafeVarargs
+ static > Predicate or(
+ Predicate first, P... components) {
+ P[] predicates = safeCopyOf((P) first, components);
+
+ return #{T t ->
+ for(P predicate : predicates) {
+ if(predicate.eval(t)) {
+ return true;
+ }
+ }
+ return false;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code true} if all or none of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end if a predicate result
+ * fails to match the first predicate's result.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param first initial component predicate to be evaluated.
+ * @param second additional component predicate to be evaluated.
+ * @return a predicate that evaluates to {@code true} if all or none of the
+ * component predicates evaluate to {@code true}
+ */
+ public static > Predicate xor(
+ Predicate first, P second) {
+ if((null != first) && (first == second)) {
+ return #{T t -> false};
+ }
+
+ Objects.requireNonNull(first);
+ Objects.requireNonNull(second);
+
+ return #{T t -> first.eval(t) ^ second.eval(t)};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code false} if all or none of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end if a predicate result
+ * fails to match the first predicate's result.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return a predicate that evaluates to {@code false} if all or none of the
+ * component predicates evaluate to {@code true}
+ */
+ public static > Predicate xor(
+ Iterable components) {
+ List
predicates = safeCopyOf(components);
+ if(predicates.isEmpty()) {
+ throw new IllegalArgumentException("no predicates");
+ }
+
+ return #{T t ->
+ Boolean initial = null;
+ for (P predicate : predicates) {
+ if (null == initial) {
+ initial = predicate.eval(t);
+ } else {
+ if (!(initial ^ predicate.eval(t))) {
+ return true;
+ }
+ }
+ }
+ return false;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code false} if all or none of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will terminate if a predicate result
+ * fails to match the first predicate's result.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return a predicate that evaluates to {@code false} if all or none of the
+ * component predicates evaluate to {@code true}
+ */
+ @SafeVarargs
+ public static > Predicate xor(P... components) {
+ P[] predicates = safeCopyOf(components);
+ if(0 == predicates.length) {
+ throw new IllegalArgumentException("no predicates");
+ }
+
+ return #{T t ->
+ Boolean initial = null;
+ for (P predicate : predicates) {
+ if (null == initial) {
+ initial = predicate.eval(t);
+ } else {
+ if (!(initial ^ predicate.eval(t))) {
+ return true;
+ }
+ }
+ }
+ return false;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code false} if all or none of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end if a predicate result
+ * fails to match the first predicate's result.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return a predicate that evaluates to {@code false} if all or none of the
+ * component predicates evaluate to {@code true}
+ */
+ @SafeVarargs
+ static > Predicate xor(
+ Predicate first,
+ P... components) {
+ P[] predicates = safeCopyOf((P) first, components);
+
+ return #{T t ->
+ Boolean initial = null;
+ for (P predicate : predicates) {
+ if (null == initial) {
+ initial = predicate.eval(t);
+ } else {
+ if (!(initial ^ predicate.eval(t))) {
+ return true;
+ }
+ }
+ }
+ return false;};
+ }
+
+ /**
+ * Returns a predicate that evaluates to {@code false} if all or none of the
+ * component predicates evaluate to {@code true}. The components are
+ * evaluated in order, and evaluation will end if a predicate result
+ * fails to match the first predicate's result.
+ *
+ * @param the type of values evaluated by the predicates.
+ * @param components The predicates to be evaluated. A copy is made of the
+ * components.
+ * @return a predicate that evaluates to {@code false} if all or none of the
+ * component predicates evaluate to {@code true}
+ */
+ static > Predicate xor(
+ Predicate first,
+ Iterable components) {
+ List
predicates = safeCopyOf((P) first, components);
+
+ return #{T t ->
+ Boolean initial = null;
+ for (P predicate : predicates) {
+ if (null == initial) {
+ initial = predicate.eval(t);
+ } else {
+ if (!(initial ^ predicate.eval(t))) {
+ return true;
+ }
+ }
+ }
+ return false;};
+ }
+
+ // XXX mduigou These need to be moved somewhere.
+
+ @SafeVarargs
+ static T[] safeCopyOf(T... array) {
+ T[] copy = Arrays.copyOf(array, array.length);
+ for(T each : copy) {
+ Objects.requireNonNull(each);
+ }
+ return copy;
+ }
+
+ @SafeVarargs
+ static T[] safeCopyOf(T first, T... array) {
+ T[] copy = (T[]) Array.newInstance(array.getClass().getComponentType(), array.length + 1);
+ copy[0] = Objects.requireNonNull(first);
+ System.arraycopy(array, 0, copy, 1, array.length);
+ for(T each : copy) {
+ Objects.requireNonNull(each);
+ }
+ return copy;
+ }
+
+ static List safeCopyOf(T first, Iterable iterable) {
+ ArrayList list = new ArrayList<>();
+ list.add(Objects.requireNonNull(first));
+
+ for (T element : iterable) {
+ list.add(Objects.requireNonNull(element));
+ }
+ return list;
+ }
+
+ static List safeCopyOf(Iterable iterable) {
+ ArrayList list = new ArrayList<>();
+ for (T element : iterable) {
+ list.add(Objects.requireNonNull(element));
+ }
+ return list;
+ }
+}