| /* |
| * Copyright (C) 2007 The Guava Authors |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/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 com.google.common.collect; |
| |
| import static com.google.common.base.Preconditions.checkArgument; |
| import static com.google.common.base.Preconditions.checkNotNull; |
| import static com.google.common.base.Predicates.compose; |
| import static com.google.common.base.Predicates.equalTo; |
| import static com.google.common.base.Predicates.in; |
| import static com.google.common.base.Predicates.not; |
| import static com.google.common.collect.CollectPreconditions.checkNonnegative; |
| |
| import com.google.common.annotations.Beta; |
| import com.google.common.annotations.GwtCompatible; |
| import com.google.common.base.Converter; |
| import com.google.common.base.Equivalence; |
| import com.google.common.base.Function; |
| import com.google.common.base.Joiner.MapJoiner; |
| import com.google.common.base.Objects; |
| import com.google.common.base.Preconditions; |
| import com.google.common.base.Predicate; |
| import com.google.common.base.Predicates; |
| import com.google.common.collect.MapDifference.ValueDifference; |
| import com.google.common.primitives.Ints; |
| |
| import java.io.Serializable; |
| import java.util.AbstractCollection; |
| import java.util.AbstractMap; |
| import java.util.Collection; |
| import java.util.Collections; |
| import java.util.Comparator; |
| import java.util.EnumMap; |
| import java.util.HashMap; |
| import java.util.IdentityHashMap; |
| import java.util.Iterator; |
| import java.util.LinkedHashMap; |
| import java.util.Map; |
| import java.util.Map.Entry; |
| import java.util.Set; |
| import java.util.SortedMap; |
| import java.util.SortedSet; |
| import java.util.TreeMap; |
| import java.util.concurrent.ConcurrentMap; |
| |
| import javax.annotation.Nullable; |
| |
| /** |
| * Static utility methods pertaining to {@link Map} instances (including instances of |
| * {@link SortedMap}, {@link BiMap}, etc.). Also see this class's counterparts |
| * {@link Lists}, {@link Sets} and {@link Queues}. |
| * |
| * <p>See the Guava User Guide article on <a href= |
| * "http://code.google.com/p/guava-libraries/wiki/CollectionUtilitiesExplained#Maps"> |
| * {@code Maps}</a>. |
| * |
| * @author Kevin Bourrillion |
| * @author Mike Bostock |
| * @author Isaac Shum |
| * @author Louis Wasserman |
| * @since 2.0 (imported from Google Collections Library) |
| */ |
| @GwtCompatible(emulated = true) |
| public final class Maps { |
| private Maps() {} |
| |
| private enum EntryFunction implements Function<Entry<?, ?>, Object> { |
| KEY { |
| @Override |
| @Nullable |
| public Object apply(Entry<?, ?> entry) { |
| return entry.getKey(); |
| } |
| }, |
| VALUE { |
| @Override |
| @Nullable |
| public Object apply(Entry<?, ?> entry) { |
| return entry.getValue(); |
| } |
| }; |
| } |
| |
| @SuppressWarnings("unchecked") |
| static <K> Function<Entry<K, ?>, K> keyFunction() { |
| return (Function) EntryFunction.KEY; |
| } |
| |
| @SuppressWarnings("unchecked") |
| static <V> Function<Entry<?, V>, V> valueFunction() { |
| return (Function) EntryFunction.VALUE; |
| } |
| |
| static <K, V> Iterator<K> keyIterator(Iterator<Entry<K, V>> entryIterator) { |
| return Iterators.transform(entryIterator, Maps.<K>keyFunction()); |
| } |
| |
| static <K, V> Iterator<V> valueIterator(Iterator<Entry<K, V>> entryIterator) { |
| return Iterators.transform(entryIterator, Maps.<V>valueFunction()); |
| } |
| |
| static <K, V> UnmodifiableIterator<V> valueIterator( |
| final UnmodifiableIterator<Entry<K, V>> entryIterator) { |
| return new UnmodifiableIterator<V>() { |
| @Override |
| public boolean hasNext() { |
| return entryIterator.hasNext(); |
| } |
| |
| @Override |
| public V next() { |
| return entryIterator.next().getValue(); |
| } |
| }; |
| } |
| |
| /** |
| * Returns an immutable map instance containing the given entries. |
| * Internally, the returned map will be backed by an {@link EnumMap}. |
| * |
| * <p>The iteration order of the returned map follows the enum's iteration |
| * order, not the order in which the elements appear in the given map. |
| * |
| * @param map the map to make an immutable copy of |
| * @return an immutable map containing those entries |
| * @since 14.0 |
| */ |
| @GwtCompatible(serializable = true) |
| @Beta |
| public static <K extends Enum<K>, V> ImmutableMap<K, V> immutableEnumMap( |
| Map<K, ? extends V> map) { |
| if (map instanceof ImmutableEnumMap) { |
| @SuppressWarnings("unchecked") // safe covariant cast |
| ImmutableEnumMap<K, V> result = (ImmutableEnumMap<K, V>) map; |
| return result; |
| } else if (map.isEmpty()) { |
| return ImmutableMap.of(); |
| } else { |
| for (Map.Entry<K, ? extends V> entry : map.entrySet()) { |
| checkNotNull(entry.getKey()); |
| checkNotNull(entry.getValue()); |
| } |
| return ImmutableEnumMap.asImmutable(new EnumMap<K, V>(map)); |
| } |
| } |
| |
| /** |
| * Creates a <i>mutable</i>, empty {@code HashMap} instance. |
| * |
| * <p><b>Note:</b> if mutability is not required, use {@link |
| * ImmutableMap#of()} instead. |
| * |
| * <p><b>Note:</b> if {@code K} is an {@code enum} type, use {@link |
| * #newEnumMap} instead. |
| * |
| * @return a new, empty {@code HashMap} |
| */ |
| public static <K, V> HashMap<K, V> newHashMap() { |
| return new HashMap<K, V>(); |
| } |
| |
| /** |
| * Creates a {@code HashMap} instance, with a high enough "initial capacity" |
| * that it <i>should</i> hold {@code expectedSize} elements without growth. |
| * This behavior cannot be broadly guaranteed, but it is observed to be true |
| * for OpenJDK 1.6. It also can't be guaranteed that the method isn't |
| * inadvertently <i>oversizing</i> the returned map. |
| * |
| * @param expectedSize the number of elements you expect to add to the |
| * returned map |
| * @return a new, empty {@code HashMap} with enough capacity to hold {@code |
| * expectedSize} elements without resizing |
| * @throws IllegalArgumentException if {@code expectedSize} is negative |
| */ |
| public static <K, V> HashMap<K, V> newHashMapWithExpectedSize( |
| int expectedSize) { |
| return new HashMap<K, V>(capacity(expectedSize)); |
| } |
| |
| /** |
| * Returns a capacity that is sufficient to keep the map from being resized as |
| * long as it grows no larger than expectedSize and the load factor is >= its |
| * default (0.75). |
| */ |
| static int capacity(int expectedSize) { |
| if (expectedSize < 3) { |
| checkNonnegative(expectedSize, "expectedSize"); |
| return expectedSize + 1; |
| } |
| if (expectedSize < Ints.MAX_POWER_OF_TWO) { |
| return expectedSize + expectedSize / 3; |
| } |
| return Integer.MAX_VALUE; // any large value |
| } |
| |
| /** |
| * Creates a <i>mutable</i> {@code HashMap} instance with the same mappings as |
| * the specified map. |
| * |
| * <p><b>Note:</b> if mutability is not required, use {@link |
| * ImmutableMap#copyOf(Map)} instead. |
| * |
| * <p><b>Note:</b> if {@code K} is an {@link Enum} type, use {@link |
| * #newEnumMap} instead. |
| * |
| * @param map the mappings to be placed in the new map |
| * @return a new {@code HashMap} initialized with the mappings from {@code |
| * map} |
| */ |
| public static <K, V> HashMap<K, V> newHashMap( |
| Map<? extends K, ? extends V> map) { |
| return new HashMap<K, V>(map); |
| } |
| |
| /** |
| * Creates a <i>mutable</i>, empty, insertion-ordered {@code LinkedHashMap} |
| * instance. |
| * |
| * <p><b>Note:</b> if mutability is not required, use {@link |
| * ImmutableMap#of()} instead. |
| * |
| * @return a new, empty {@code LinkedHashMap} |
| */ |
| public static <K, V> LinkedHashMap<K, V> newLinkedHashMap() { |
| return new LinkedHashMap<K, V>(); |
| } |
| |
| /** |
| * Creates a <i>mutable</i>, insertion-ordered {@code LinkedHashMap} instance |
| * with the same mappings as the specified map. |
| * |
| * <p><b>Note:</b> if mutability is not required, use {@link |
| * ImmutableMap#copyOf(Map)} instead. |
| * |
| * @param map the mappings to be placed in the new map |
| * @return a new, {@code LinkedHashMap} initialized with the mappings from |
| * {@code map} |
| */ |
| public static <K, V> LinkedHashMap<K, V> newLinkedHashMap( |
| Map<? extends K, ? extends V> map) { |
| return new LinkedHashMap<K, V>(map); |
| } |
| |
| /** |
| * Returns a general-purpose instance of {@code ConcurrentMap}, which supports |
| * all optional operations of the ConcurrentMap interface. It does not permit |
| * null keys or values. It is serializable. |
| * |
| * <p>This is currently accomplished by calling {@link MapMaker#makeMap()}. |
| * |
| * <p>It is preferable to use {@code MapMaker} directly (rather than through |
| * this method), as it presents numerous useful configuration options, |
| * such as the concurrency level, load factor, key/value reference types, |
| * and value computation. |
| * |
| * @return a new, empty {@code ConcurrentMap} |
| * @since 3.0 |
| */ |
| public static <K, V> ConcurrentMap<K, V> newConcurrentMap() { |
| return new MapMaker().<K, V>makeMap(); |
| } |
| |
| /** |
| * Creates a <i>mutable</i>, empty {@code TreeMap} instance using the natural |
| * ordering of its elements. |
| * |
| * <p><b>Note:</b> if mutability is not required, use {@link |
| * ImmutableSortedMap#of()} instead. |
| * |
| * @return a new, empty {@code TreeMap} |
| */ |
| public static <K extends Comparable, V> TreeMap<K, V> newTreeMap() { |
| return new TreeMap<K, V>(); |
| } |
| |
| /** |
| * Creates a <i>mutable</i> {@code TreeMap} instance with the same mappings as |
| * the specified map and using the same ordering as the specified map. |
| * |
| * <p><b>Note:</b> if mutability is not required, use {@link |
| * ImmutableSortedMap#copyOfSorted(SortedMap)} instead. |
| * |
| * @param map the sorted map whose mappings are to be placed in the new map |
| * and whose comparator is to be used to sort the new map |
| * @return a new {@code TreeMap} initialized with the mappings from {@code |
| * map} and using the comparator of {@code map} |
| */ |
| public static <K, V> TreeMap<K, V> newTreeMap(SortedMap<K, ? extends V> map) { |
| return new TreeMap<K, V>(map); |
| } |
| |
| /** |
| * Creates a <i>mutable</i>, empty {@code TreeMap} instance using the given |
| * comparator. |
| * |
| * <p><b>Note:</b> if mutability is not required, use {@code |
| * ImmutableSortedMap.orderedBy(comparator).build()} instead. |
| * |
| * @param comparator the comparator to sort the keys with |
| * @return a new, empty {@code TreeMap} |
| */ |
| public static <C, K extends C, V> TreeMap<K, V> newTreeMap( |
| @Nullable Comparator<C> comparator) { |
| // Ideally, the extra type parameter "C" shouldn't be necessary. It is a |
| // work-around of a compiler type inference quirk that prevents the |
| // following code from being compiled: |
| // Comparator<Class<?>> comparator = null; |
| // Map<Class<? extends Throwable>, String> map = newTreeMap(comparator); |
| return new TreeMap<K, V>(comparator); |
| } |
| |
| /** |
| * Creates an {@code EnumMap} instance. |
| * |
| * @param type the key type for this map |
| * @return a new, empty {@code EnumMap} |
| */ |
| public static <K extends Enum<K>, V> EnumMap<K, V> newEnumMap(Class<K> type) { |
| return new EnumMap<K, V>(checkNotNull(type)); |
| } |
| |
| /** |
| * Creates an {@code EnumMap} with the same mappings as the specified map. |
| * |
| * @param map the map from which to initialize this {@code EnumMap} |
| * @return a new {@code EnumMap} initialized with the mappings from {@code |
| * map} |
| * @throws IllegalArgumentException if {@code m} is not an {@code EnumMap} |
| * instance and contains no mappings |
| */ |
| public static <K extends Enum<K>, V> EnumMap<K, V> newEnumMap( |
| Map<K, ? extends V> map) { |
| return new EnumMap<K, V>(map); |
| } |
| |
| /** |
| * Creates an {@code IdentityHashMap} instance. |
| * |
| * @return a new, empty {@code IdentityHashMap} |
| */ |
| public static <K, V> IdentityHashMap<K, V> newIdentityHashMap() { |
| return new IdentityHashMap<K, V>(); |
| } |
| |
| /** |
| * Computes the difference between two maps. This difference is an immutable |
| * snapshot of the state of the maps at the time this method is called. It |
| * will never change, even if the maps change at a later time. |
| * |
| * <p>Since this method uses {@code HashMap} instances internally, the keys of |
| * the supplied maps must be well-behaved with respect to |
| * {@link Object#equals} and {@link Object#hashCode}. |
| * |
| * <p><b>Note:</b>If you only need to know whether two maps have the same |
| * mappings, call {@code left.equals(right)} instead of this method. |
| * |
| * @param left the map to treat as the "left" map for purposes of comparison |
| * @param right the map to treat as the "right" map for purposes of comparison |
| * @return the difference between the two maps |
| */ |
| @SuppressWarnings("unchecked") |
| public static <K, V> MapDifference<K, V> difference( |
| Map<? extends K, ? extends V> left, Map<? extends K, ? extends V> right) { |
| if (left instanceof SortedMap) { |
| SortedMap<K, ? extends V> sortedLeft = (SortedMap<K, ? extends V>) left; |
| SortedMapDifference<K, V> result = difference(sortedLeft, right); |
| return result; |
| } |
| return difference(left, right, Equivalence.equals()); |
| } |
| |
| /** |
| * Computes the difference between two maps. This difference is an immutable |
| * snapshot of the state of the maps at the time this method is called. It |
| * will never change, even if the maps change at a later time. |
| * |
| * <p>Values are compared using a provided equivalence, in the case of |
| * equality, the value on the 'left' is returned in the difference. |
| * |
| * <p>Since this method uses {@code HashMap} instances internally, the keys of |
| * the supplied maps must be well-behaved with respect to |
| * {@link Object#equals} and {@link Object#hashCode}. |
| * |
| * @param left the map to treat as the "left" map for purposes of comparison |
| * @param right the map to treat as the "right" map for purposes of comparison |
| * @param valueEquivalence the equivalence relationship to use to compare |
| * values |
| * @return the difference between the two maps |
| * @since 10.0 |
| */ |
| @Beta |
| public static <K, V> MapDifference<K, V> difference( |
| Map<? extends K, ? extends V> left, Map<? extends K, ? extends V> right, |
| Equivalence<? super V> valueEquivalence) { |
| Preconditions.checkNotNull(valueEquivalence); |
| |
| Map<K, V> onlyOnLeft = newHashMap(); |
| Map<K, V> onlyOnRight = new HashMap<K, V>(right); // will whittle it down |
| Map<K, V> onBoth = newHashMap(); |
| Map<K, MapDifference.ValueDifference<V>> differences = newHashMap(); |
| doDifference(left, right, valueEquivalence, onlyOnLeft, onlyOnRight, onBoth, differences); |
| return new MapDifferenceImpl<K, V>(onlyOnLeft, onlyOnRight, onBoth, differences); |
| } |
| |
| private static <K, V> void doDifference( |
| Map<? extends K, ? extends V> left, Map<? extends K, ? extends V> right, |
| Equivalence<? super V> valueEquivalence, |
| Map<K, V> onlyOnLeft, Map<K, V> onlyOnRight, Map<K, V> onBoth, |
| Map<K, MapDifference.ValueDifference<V>> differences) { |
| for (Entry<? extends K, ? extends V> entry : left.entrySet()) { |
| K leftKey = entry.getKey(); |
| V leftValue = entry.getValue(); |
| if (right.containsKey(leftKey)) { |
| V rightValue = onlyOnRight.remove(leftKey); |
| if (valueEquivalence.equivalent(leftValue, rightValue)) { |
| onBoth.put(leftKey, leftValue); |
| } else { |
| differences.put( |
| leftKey, ValueDifferenceImpl.create(leftValue, rightValue)); |
| } |
| } else { |
| onlyOnLeft.put(leftKey, leftValue); |
| } |
| } |
| } |
| |
| private static <K, V> Map<K, V> unmodifiableMap(Map<K, V> map) { |
| if (map instanceof SortedMap) { |
| return Collections.unmodifiableSortedMap((SortedMap<K, ? extends V>) map); |
| } else { |
| return Collections.unmodifiableMap(map); |
| } |
| } |
| |
| static class MapDifferenceImpl<K, V> implements MapDifference<K, V> { |
| final Map<K, V> onlyOnLeft; |
| final Map<K, V> onlyOnRight; |
| final Map<K, V> onBoth; |
| final Map<K, ValueDifference<V>> differences; |
| |
| MapDifferenceImpl(Map<K, V> onlyOnLeft, |
| Map<K, V> onlyOnRight, Map<K, V> onBoth, |
| Map<K, ValueDifference<V>> differences) { |
| this.onlyOnLeft = unmodifiableMap(onlyOnLeft); |
| this.onlyOnRight = unmodifiableMap(onlyOnRight); |
| this.onBoth = unmodifiableMap(onBoth); |
| this.differences = unmodifiableMap(differences); |
| } |
| |
| @Override |
| public boolean areEqual() { |
| return onlyOnLeft.isEmpty() && onlyOnRight.isEmpty() && differences.isEmpty(); |
| } |
| |
| @Override |
| public Map<K, V> entriesOnlyOnLeft() { |
| return onlyOnLeft; |
| } |
| |
| @Override |
| public Map<K, V> entriesOnlyOnRight() { |
| return onlyOnRight; |
| } |
| |
| @Override |
| public Map<K, V> entriesInCommon() { |
| return onBoth; |
| } |
| |
| @Override |
| public Map<K, ValueDifference<V>> entriesDiffering() { |
| return differences; |
| } |
| |
| @Override public boolean equals(Object object) { |
| if (object == this) { |
| return true; |
| } |
| if (object instanceof MapDifference) { |
| MapDifference<?, ?> other = (MapDifference<?, ?>) object; |
| return entriesOnlyOnLeft().equals(other.entriesOnlyOnLeft()) |
| && entriesOnlyOnRight().equals(other.entriesOnlyOnRight()) |
| && entriesInCommon().equals(other.entriesInCommon()) |
| && entriesDiffering().equals(other.entriesDiffering()); |
| } |
| return false; |
| } |
| |
| @Override public int hashCode() { |
| return Objects.hashCode(entriesOnlyOnLeft(), entriesOnlyOnRight(), |
| entriesInCommon(), entriesDiffering()); |
| } |
| |
| @Override public String toString() { |
| if (areEqual()) { |
| return "equal"; |
| } |
| |
| StringBuilder result = new StringBuilder("not equal"); |
| if (!onlyOnLeft.isEmpty()) { |
| result.append(": only on left=").append(onlyOnLeft); |
| } |
| if (!onlyOnRight.isEmpty()) { |
| result.append(": only on right=").append(onlyOnRight); |
| } |
| if (!differences.isEmpty()) { |
| result.append(": value differences=").append(differences); |
| } |
| return result.toString(); |
| } |
| } |
| |
| static class ValueDifferenceImpl<V> |
| implements MapDifference.ValueDifference<V> { |
| private final V left; |
| private final V right; |
| |
| static <V> ValueDifference<V> create(@Nullable V left, @Nullable V right) { |
| return new ValueDifferenceImpl<V>(left, right); |
| } |
| |
| private ValueDifferenceImpl(@Nullable V left, @Nullable V right) { |
| this.left = left; |
| this.right = right; |
| } |
| |
| @Override |
| public V leftValue() { |
| return left; |
| } |
| |
| @Override |
| public V rightValue() { |
| return right; |
| } |
| |
| @Override public boolean equals(@Nullable Object object) { |
| if (object instanceof MapDifference.ValueDifference) { |
| MapDifference.ValueDifference<?> that = |
| (MapDifference.ValueDifference<?>) object; |
| return Objects.equal(this.left, that.leftValue()) |
| && Objects.equal(this.right, that.rightValue()); |
| } |
| return false; |
| } |
| |
| @Override public int hashCode() { |
| return Objects.hashCode(left, right); |
| } |
| |
| @Override public String toString() { |
| return "(" + left + ", " + right + ")"; |
| } |
| } |
| |
| /** |
| * Computes the difference between two sorted maps, using the comparator of |
| * the left map, or {@code Ordering.natural()} if the left map uses the |
| * natural ordering of its elements. This difference is an immutable snapshot |
| * of the state of the maps at the time this method is called. It will never |
| * change, even if the maps change at a later time. |
| * |
| * <p>Since this method uses {@code TreeMap} instances internally, the keys of |
| * the right map must all compare as distinct according to the comparator |
| * of the left map. |
| * |
| * <p><b>Note:</b>If you only need to know whether two sorted maps have the |
| * same mappings, call {@code left.equals(right)} instead of this method. |
| * |
| * @param left the map to treat as the "left" map for purposes of comparison |
| * @param right the map to treat as the "right" map for purposes of comparison |
| * @return the difference between the two maps |
| * @since 11.0 |
| */ |
| public static <K, V> SortedMapDifference<K, V> difference( |
| SortedMap<K, ? extends V> left, Map<? extends K, ? extends V> right) { |
| checkNotNull(left); |
| checkNotNull(right); |
| Comparator<? super K> comparator = orNaturalOrder(left.comparator()); |
| SortedMap<K, V> onlyOnLeft = Maps.newTreeMap(comparator); |
| SortedMap<K, V> onlyOnRight = Maps.newTreeMap(comparator); |
| onlyOnRight.putAll(right); // will whittle it down |
| SortedMap<K, V> onBoth = Maps.newTreeMap(comparator); |
| SortedMap<K, MapDifference.ValueDifference<V>> differences = |
| Maps.newTreeMap(comparator); |
| doDifference(left, right, Equivalence.equals(), onlyOnLeft, onlyOnRight, onBoth, differences); |
| return new SortedMapDifferenceImpl<K, V>(onlyOnLeft, onlyOnRight, onBoth, differences); |
| } |
| |
| static class SortedMapDifferenceImpl<K, V> extends MapDifferenceImpl<K, V> |
| implements SortedMapDifference<K, V> { |
| SortedMapDifferenceImpl(SortedMap<K, V> onlyOnLeft, |
| SortedMap<K, V> onlyOnRight, SortedMap<K, V> onBoth, |
| SortedMap<K, ValueDifference<V>> differences) { |
| super(onlyOnLeft, onlyOnRight, onBoth, differences); |
| } |
| |
| @Override public SortedMap<K, ValueDifference<V>> entriesDiffering() { |
| return (SortedMap<K, ValueDifference<V>>) super.entriesDiffering(); |
| } |
| |
| @Override public SortedMap<K, V> entriesInCommon() { |
| return (SortedMap<K, V>) super.entriesInCommon(); |
| } |
| |
| @Override public SortedMap<K, V> entriesOnlyOnLeft() { |
| return (SortedMap<K, V>) super.entriesOnlyOnLeft(); |
| } |
| |
| @Override public SortedMap<K, V> entriesOnlyOnRight() { |
| return (SortedMap<K, V>) super.entriesOnlyOnRight(); |
| } |
| } |
| |
| /** |
| * Returns the specified comparator if not null; otherwise returns {@code |
| * Ordering.natural()}. This method is an abomination of generics; the only |
| * purpose of this method is to contain the ugly type-casting in one place. |
| */ |
| @SuppressWarnings("unchecked") |
| static <E> Comparator<? super E> orNaturalOrder( |
| @Nullable Comparator<? super E> comparator) { |
| if (comparator != null) { // can't use ? : because of javac bug 5080917 |
| return comparator; |
| } |
| return (Comparator<E>) Ordering.natural(); |
| } |
| |
| /** |
| * Returns a live {@link Map} view whose keys are the contents of {@code set} |
| * and whose values are computed on demand using {@code function}. To get an |
| * immutable <i>copy</i> instead, use {@link #toMap(Iterable, Function)}. |
| * |
| * <p>Specifically, for each {@code k} in the backing set, the returned map |
| * has an entry mapping {@code k} to {@code function.apply(k)}. The {@code |
| * keySet}, {@code values}, and {@code entrySet} views of the returned map |
| * iterate in the same order as the backing set. |
| * |
| * <p>Modifications to the backing set are read through to the returned map. |
| * The returned map supports removal operations if the backing set does. |
| * Removal operations write through to the backing set. The returned map |
| * does not support put operations. |
| * |
| * <p><b>Warning:</b> If the function rejects {@code null}, caution is |
| * required to make sure the set does not contain {@code null}, because the |
| * view cannot stop {@code null} from being added to the set. |
| * |
| * <p><b>Warning:</b> This method assumes that for any instance {@code k} of |
| * key type {@code K}, {@code k.equals(k2)} implies that {@code k2} is also |
| * of type {@code K}. Using a key type for which this may not hold, such as |
| * {@code ArrayList}, may risk a {@code ClassCastException} when calling |
| * methods on the resulting map view. |
| * |
| * @since 14.0 |
| */ |
| @Beta |
| public static <K, V> Map<K, V> asMap( |
| Set<K> set, Function<? super K, V> function) { |
| if (set instanceof SortedSet) { |
| return asMap((SortedSet<K>) set, function); |
| } else { |
| return new AsMapView<K, V>(set, function); |
| } |
| } |
| |
| /** |
| * Returns a view of the sorted set as a map, mapping keys from the set |
| * according to the specified function. |
| * |
| * <p>Specifically, for each {@code k} in the backing set, the returned map |
| * has an entry mapping {@code k} to {@code function.apply(k)}. The {@code |
| * keySet}, {@code values}, and {@code entrySet} views of the returned map |
| * iterate in the same order as the backing set. |
| * |
| * <p>Modifications to the backing set are read through to the returned map. |
| * The returned map supports removal operations if the backing set does. |
| * Removal operations write through to the backing set. The returned map does |
| * not support put operations. |
| * |
| * <p><b>Warning:</b> If the function rejects {@code null}, caution is |
| * required to make sure the set does not contain {@code null}, because the |
| * view cannot stop {@code null} from being added to the set. |
| * |
| * <p><b>Warning:</b> This method assumes that for any instance {@code k} of |
| * key type {@code K}, {@code k.equals(k2)} implies that {@code k2} is also of |
| * type {@code K}. Using a key type for which this may not hold, such as |
| * {@code ArrayList}, may risk a {@code ClassCastException} when calling |
| * methods on the resulting map view. |
| * |
| * @since 14.0 |
| */ |
| @Beta |
| public static <K, V> SortedMap<K, V> asMap( |
| SortedSet<K> set, Function<? super K, V> function) { |
| return Platform.mapsAsMapSortedSet(set, function); |
| } |
| |
| static <K, V> SortedMap<K, V> asMapSortedIgnoreNavigable(SortedSet<K> set, |
| Function<? super K, V> function) { |
| return new SortedAsMapView<K, V>(set, function); |
| } |
| |
| private static class AsMapView<K, V> extends ImprovedAbstractMap<K, V> { |
| |
| private final Set<K> set; |
| final Function<? super K, V> function; |
| |
| Set<K> backingSet() { |
| return set; |
| } |
| |
| AsMapView(Set<K> set, Function<? super K, V> function) { |
| this.set = checkNotNull(set); |
| this.function = checkNotNull(function); |
| } |
| |
| @Override |
| public Set<K> createKeySet() { |
| return removeOnlySet(backingSet()); |
| } |
| |
| @Override |
| Collection<V> createValues() { |
| return Collections2.transform(set, function); |
| } |
| |
| @Override |
| public int size() { |
| return backingSet().size(); |
| } |
| |
| @Override |
| public boolean containsKey(@Nullable Object key) { |
| return backingSet().contains(key); |
| } |
| |
| @Override |
| public V get(@Nullable Object key) { |
| if (Collections2.safeContains(backingSet(), key)) { |
| @SuppressWarnings("unchecked") // unsafe, but Javadoc warns about it |
| K k = (K) key; |
| return function.apply(k); |
| } else { |
| return null; |
| } |
| } |
| |
| @Override |
| public V remove(@Nullable Object key) { |
| if (backingSet().remove(key)) { |
| @SuppressWarnings("unchecked") // unsafe, but Javadoc warns about it |
| K k = (K) key; |
| return function.apply(k); |
| } else { |
| return null; |
| } |
| } |
| |
| @Override |
| public void clear() { |
| backingSet().clear(); |
| } |
| |
| @Override |
| protected Set<Entry<K, V>> createEntrySet() { |
| return new EntrySet<K, V>() { |
| @Override |
| Map<K, V> map() { |
| return AsMapView.this; |
| } |
| |
| @Override |
| public Iterator<Entry<K, V>> iterator() { |
| return asMapEntryIterator(backingSet(), function); |
| } |
| }; |
| } |
| } |
| |
| static <K, V> Iterator<Entry<K, V>> asMapEntryIterator( |
| Set<K> set, final Function<? super K, V> function) { |
| return new TransformedIterator<K, Entry<K,V>>(set.iterator()) { |
| @Override |
| Entry<K, V> transform(final K key) { |
| return immutableEntry(key, function.apply(key)); |
| } |
| }; |
| } |
| |
| private static class SortedAsMapView<K, V> extends AsMapView<K, V> |
| implements SortedMap<K, V> { |
| |
| SortedAsMapView(SortedSet<K> set, Function<? super K, V> function) { |
| super(set, function); |
| } |
| |
| @Override |
| SortedSet<K> backingSet() { |
| return (SortedSet<K>) super.backingSet(); |
| } |
| |
| @Override |
| public Comparator<? super K> comparator() { |
| return backingSet().comparator(); |
| } |
| |
| @Override |
| public Set<K> keySet() { |
| return removeOnlySortedSet(backingSet()); |
| } |
| |
| @Override |
| public SortedMap<K, V> subMap(K fromKey, K toKey) { |
| return asMap(backingSet().subSet(fromKey, toKey), function); |
| } |
| |
| @Override |
| public SortedMap<K, V> headMap(K toKey) { |
| return asMap(backingSet().headSet(toKey), function); |
| } |
| |
| @Override |
| public SortedMap<K, V> tailMap(K fromKey) { |
| return asMap(backingSet().tailSet(fromKey), function); |
| } |
| |
| @Override |
| public K firstKey() { |
| return backingSet().first(); |
| } |
| |
| @Override |
| public K lastKey() { |
| return backingSet().last(); |
| } |
| } |
| |
| private static <E> Set<E> removeOnlySet(final Set<E> set) { |
| return new ForwardingSet<E>() { |
| @Override |
| protected Set<E> delegate() { |
| return set; |
| } |
| |
| @Override |
| public boolean add(E element) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean addAll(Collection<? extends E> es) { |
| throw new UnsupportedOperationException(); |
| } |
| }; |
| } |
| |
| private static <E> SortedSet<E> removeOnlySortedSet(final SortedSet<E> set) { |
| return new ForwardingSortedSet<E>() { |
| @Override |
| protected SortedSet<E> delegate() { |
| return set; |
| } |
| |
| @Override |
| public boolean add(E element) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public boolean addAll(Collection<? extends E> es) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public SortedSet<E> headSet(E toElement) { |
| return removeOnlySortedSet(super.headSet(toElement)); |
| } |
| |
| @Override |
| public SortedSet<E> subSet(E fromElement, E toElement) { |
| return removeOnlySortedSet(super.subSet(fromElement, toElement)); |
| } |
| |
| @Override |
| public SortedSet<E> tailSet(E fromElement) { |
| return removeOnlySortedSet(super.tailSet(fromElement)); |
| } |
| }; |
| } |
| |
| /** |
| * Returns an immutable map whose keys are the distinct elements of {@code |
| * keys} and whose value for each key was computed by {@code valueFunction}. |
| * The map's iteration order is the order of the first appearance of each key |
| * in {@code keys}. |
| * |
| * <p>If {@code keys} is a {@link Set}, a live view can be obtained instead of |
| * a copy using {@link Maps#asMap(Set, Function)}. |
| * |
| * @throws NullPointerException if any element of {@code keys} is |
| * {@code null}, or if {@code valueFunction} produces {@code null} |
| * for any key |
| * @since 14.0 |
| */ |
| @Beta |
| public static <K, V> ImmutableMap<K, V> toMap(Iterable<K> keys, |
| Function<? super K, V> valueFunction) { |
| return toMap(keys.iterator(), valueFunction); |
| } |
| |
| /** |
| * Returns an immutable map whose keys are the distinct elements of {@code |
| * keys} and whose value for each key was computed by {@code valueFunction}. |
| * The map's iteration order is the order of the first appearance of each key |
| * in {@code keys}. |
| * |
| * @throws NullPointerException if any element of {@code keys} is |
| * {@code null}, or if {@code valueFunction} produces {@code null} |
| * for any key |
| * @since 14.0 |
| */ |
| @Beta |
| public static <K, V> ImmutableMap<K, V> toMap(Iterator<K> keys, |
| Function<? super K, V> valueFunction) { |
| checkNotNull(valueFunction); |
| // Using LHM instead of a builder so as not to fail on duplicate keys |
| Map<K, V> builder = newLinkedHashMap(); |
| while (keys.hasNext()) { |
| K key = keys.next(); |
| builder.put(key, valueFunction.apply(key)); |
| } |
| return ImmutableMap.copyOf(builder); |
| } |
| |
| /** |
| * Returns an immutable map for which the {@link Map#values} are the given |
| * elements in the given order, and each key is the product of invoking a |
| * supplied function on its corresponding value. |
| * |
| * @param values the values to use when constructing the {@code Map} |
| * @param keyFunction the function used to produce the key for each value |
| * @return a map mapping the result of evaluating the function {@code |
| * keyFunction} on each value in the input collection to that value |
| * @throws IllegalArgumentException if {@code keyFunction} produces the same |
| * key for more than one value in the input collection |
| * @throws NullPointerException if any elements of {@code values} is null, or |
| * if {@code keyFunction} produces {@code null} for any value |
| */ |
| public static <K, V> ImmutableMap<K, V> uniqueIndex( |
| Iterable<V> values, Function<? super V, K> keyFunction) { |
| return uniqueIndex(values.iterator(), keyFunction); |
| } |
| |
| /** |
| * Returns an immutable map for which the {@link Map#values} are the given |
| * elements in the given order, and each key is the product of invoking a |
| * supplied function on its corresponding value. |
| * |
| * @param values the values to use when constructing the {@code Map} |
| * @param keyFunction the function used to produce the key for each value |
| * @return a map mapping the result of evaluating the function {@code |
| * keyFunction} on each value in the input collection to that value |
| * @throws IllegalArgumentException if {@code keyFunction} produces the same |
| * key for more than one value in the input collection |
| * @throws NullPointerException if any elements of {@code values} is null, or |
| * if {@code keyFunction} produces {@code null} for any value |
| * @since 10.0 |
| */ |
| public static <K, V> ImmutableMap<K, V> uniqueIndex( |
| Iterator<V> values, Function<? super V, K> keyFunction) { |
| checkNotNull(keyFunction); |
| ImmutableMap.Builder<K, V> builder = ImmutableMap.builder(); |
| while (values.hasNext()) { |
| V value = values.next(); |
| builder.put(keyFunction.apply(value), value); |
| } |
| return builder.build(); |
| } |
| |
| /** |
| * Returns an immutable map entry with the specified key and value. The {@link |
| * Entry#setValue} operation throws an {@link UnsupportedOperationException}. |
| * |
| * <p>The returned entry is serializable. |
| * |
| * @param key the key to be associated with the returned entry |
| * @param value the value to be associated with the returned entry |
| */ |
| @GwtCompatible(serializable = true) |
| public static <K, V> Entry<K, V> immutableEntry( |
| @Nullable K key, @Nullable V value) { |
| return new ImmutableEntry<K, V>(key, value); |
| } |
| |
| /** |
| * Returns an unmodifiable view of the specified set of entries. The {@link |
| * Entry#setValue} operation throws an {@link UnsupportedOperationException}, |
| * as do any operations that would modify the returned set. |
| * |
| * @param entrySet the entries for which to return an unmodifiable view |
| * @return an unmodifiable view of the entries |
| */ |
| static <K, V> Set<Entry<K, V>> unmodifiableEntrySet( |
| Set<Entry<K, V>> entrySet) { |
| return new UnmodifiableEntrySet<K, V>( |
| Collections.unmodifiableSet(entrySet)); |
| } |
| |
| /** |
| * Returns an unmodifiable view of the specified map entry. The {@link |
| * Entry#setValue} operation throws an {@link UnsupportedOperationException}. |
| * This also has the side-effect of redefining {@code equals} to comply with |
| * the Entry contract, to avoid a possible nefarious implementation of equals. |
| * |
| * @param entry the entry for which to return an unmodifiable view |
| * @return an unmodifiable view of the entry |
| */ |
| static <K, V> Entry<K, V> unmodifiableEntry(final Entry<? extends K, ? extends V> entry) { |
| checkNotNull(entry); |
| return new AbstractMapEntry<K, V>() { |
| @Override public K getKey() { |
| return entry.getKey(); |
| } |
| |
| @Override public V getValue() { |
| return entry.getValue(); |
| } |
| }; |
| } |
| |
| /** @see Multimaps#unmodifiableEntries */ |
| static class UnmodifiableEntries<K, V> |
| extends ForwardingCollection<Entry<K, V>> { |
| private final Collection<Entry<K, V>> entries; |
| |
| UnmodifiableEntries(Collection<Entry<K, V>> entries) { |
| this.entries = entries; |
| } |
| |
| @Override protected Collection<Entry<K, V>> delegate() { |
| return entries; |
| } |
| |
| @Override public Iterator<Entry<K, V>> iterator() { |
| final Iterator<Entry<K, V>> delegate = super.iterator(); |
| return new UnmodifiableIterator<Entry<K, V>>() { |
| @Override |
| public boolean hasNext() { |
| return delegate.hasNext(); |
| } |
| |
| @Override public Entry<K, V> next() { |
| return unmodifiableEntry(delegate.next()); |
| } |
| }; |
| } |
| |
| // See java.util.Collections.UnmodifiableEntrySet for details on attacks. |
| |
| @Override public Object[] toArray() { |
| return standardToArray(); |
| } |
| |
| @Override public <T> T[] toArray(T[] array) { |
| return standardToArray(array); |
| } |
| } |
| |
| /** @see Maps#unmodifiableEntrySet(Set) */ |
| static class UnmodifiableEntrySet<K, V> |
| extends UnmodifiableEntries<K, V> implements Set<Entry<K, V>> { |
| UnmodifiableEntrySet(Set<Entry<K, V>> entries) { |
| super(entries); |
| } |
| |
| // See java.util.Collections.UnmodifiableEntrySet for details on attacks. |
| |
| @Override public boolean equals(@Nullable Object object) { |
| return Sets.equalsImpl(this, object); |
| } |
| |
| @Override public int hashCode() { |
| return Sets.hashCodeImpl(this); |
| } |
| } |
| |
| /** |
| * Returns a {@link Converter} that converts values using {@link BiMap#get bimap.get()}, |
| * and whose inverse view converts values using |
| * {@link BiMap#inverse bimap.inverse()}{@code .get()}. |
| * |
| * <p>To use a plain {@link Map} as a {@link Function}, see |
| * {@link com.google.common.base.Functions#forMap(Map)} or |
| * {@link com.google.common.base.Functions#forMap(Map, Object)}. |
| * |
| * @since 16.0 |
| */ |
| @Beta |
| public static <A, B> Converter<A, B> asConverter(final BiMap<A, B> bimap) { |
| return new BiMapConverter<A, B>(bimap); |
| } |
| |
| private static final class BiMapConverter<A, B> extends Converter<A, B> implements Serializable { |
| private final BiMap<A, B> bimap; |
| |
| BiMapConverter(BiMap<A, B> bimap) { |
| this.bimap = checkNotNull(bimap); |
| } |
| |
| @Override |
| protected B doForward(A a) { |
| return convert(bimap, a); |
| } |
| |
| @Override |
| protected A doBackward(B b) { |
| return convert(bimap.inverse(), b); |
| } |
| |
| private static <X, Y> Y convert(BiMap<X, Y> bimap, X input) { |
| Y output = bimap.get(input); |
| checkArgument(output != null, "No non-null mapping present for input: %s", input); |
| return output; |
| } |
| |
| @Override |
| public boolean equals(@Nullable Object object) { |
| if (object instanceof BiMapConverter) { |
| BiMapConverter<?, ?> that = (BiMapConverter<?, ?>) object; |
| return this.bimap.equals(that.bimap); |
| } |
| return false; |
| } |
| |
| @Override |
| public int hashCode() { |
| return bimap.hashCode(); |
| } |
| |
| // There's really no good way to implement toString() without printing the entire BiMap, right? |
| @Override |
| public String toString() { |
| return "Maps.asConverter(" + bimap + ")"; |
| } |
| |
| private static final long serialVersionUID = 0L; |
| } |
| |
| /** |
| * Returns a synchronized (thread-safe) bimap backed by the specified bimap. |
| * In order to guarantee serial access, it is critical that <b>all</b> access |
| * to the backing bimap is accomplished through the returned bimap. |
| * |
| * <p>It is imperative that the user manually synchronize on the returned map |
| * when accessing any of its collection views: <pre> {@code |
| * |
| * BiMap<Long, String> map = Maps.synchronizedBiMap( |
| * HashBiMap.<Long, String>create()); |
| * ... |
| * Set<Long> set = map.keySet(); // Needn't be in synchronized block |
| * ... |
| * synchronized (map) { // Synchronizing on map, not set! |
| * Iterator<Long> it = set.iterator(); // Must be in synchronized block |
| * while (it.hasNext()) { |
| * foo(it.next()); |
| * } |
| * }}</pre> |
| * |
| * <p>Failure to follow this advice may result in non-deterministic behavior. |
| * |
| * <p>The returned bimap will be serializable if the specified bimap is |
| * serializable. |
| * |
| * @param bimap the bimap to be wrapped in a synchronized view |
| * @return a sychronized view of the specified bimap |
| */ |
| public static <K, V> BiMap<K, V> synchronizedBiMap(BiMap<K, V> bimap) { |
| return Synchronized.biMap(bimap, null); |
| } |
| |
| /** |
| * Returns an unmodifiable view of the specified bimap. This method allows |
| * modules to provide users with "read-only" access to internal bimaps. Query |
| * operations on the returned bimap "read through" to the specified bimap, and |
| * attempts to modify the returned map, whether direct or via its collection |
| * views, result in an {@code UnsupportedOperationException}. |
| * |
| * <p>The returned bimap will be serializable if the specified bimap is |
| * serializable. |
| * |
| * @param bimap the bimap for which an unmodifiable view is to be returned |
| * @return an unmodifiable view of the specified bimap |
| */ |
| public static <K, V> BiMap<K, V> unmodifiableBiMap( |
| BiMap<? extends K, ? extends V> bimap) { |
| return new UnmodifiableBiMap<K, V>(bimap, null); |
| } |
| |
| /** @see Maps#unmodifiableBiMap(BiMap) */ |
| private static class UnmodifiableBiMap<K, V> |
| extends ForwardingMap<K, V> implements BiMap<K, V>, Serializable { |
| final Map<K, V> unmodifiableMap; |
| final BiMap<? extends K, ? extends V> delegate; |
| BiMap<V, K> inverse; |
| transient Set<V> values; |
| |
| UnmodifiableBiMap(BiMap<? extends K, ? extends V> delegate, |
| @Nullable BiMap<V, K> inverse) { |
| unmodifiableMap = Collections.unmodifiableMap(delegate); |
| this.delegate = delegate; |
| this.inverse = inverse; |
| } |
| |
| @Override protected Map<K, V> delegate() { |
| return unmodifiableMap; |
| } |
| |
| @Override |
| public V forcePut(K key, V value) { |
| throw new UnsupportedOperationException(); |
| } |
| |
| @Override |
| public BiMap<V, K> inverse() { |
| BiMap<V, K> result = inverse; |
| return (result == null) |
| ? inverse = new UnmodifiableBiMap<V, K>(delegate.inverse(), this) |
| : result; |
| } |
| |
| @Override public Set<V> values() { |
| Set<V> result = values; |
| return (result == null) |
| ? values = Collections.unmodifiableSet(delegate.values()) |
| : result; |
| } |
| |
| private static final long serialVersionUID = 0; |
| } |
| |
| /** |
| * Returns a view of a map where each value is transformed by a function. All |
| * other properties of the map, such as iteration order, are left intact. For |
| * example, the code: <pre> {@code |
| * |
| * Map<String, Integer> map = ImmutableMap.of("a", 4, "b", 9); |
| * Function<Integer, Double> sqrt = |
| * new Function<Integer, Double>() { |
| * public Double apply(Integer in) { |
| * return Math.sqrt((int) in); |
| * } |
| * }; |
| * Map<String, Double> transformed = Maps.transformValues(map, sqrt); |
| * System.out.println(transformed);}</pre> |
| * |
| * ... prints {@code {a=2.0, b=3.0}}. |
| * |
| * <p>Changes in the underlying map are reflected in this view. Conversely, |
| * this view supports removal operations, and these are reflected in the |
| * underlying map. |
| * |
| * <p>It's acceptable for the underlying map to contain null keys, and even |
| * null values provided that the function is capable of accepting null input. |
| * The transformed map might contain null values, if the function sometimes |
| * gives a null result. |
| * |
| * <p>The returned map is not thread-safe or serializable, even if the |
| * underlying map is. |
| * |
| * <p>The function is applied lazily, invoked when needed. This is necessary |
| * for the returned map to be a view, but it means that the function will be |
| * applied many times for bulk operations like {@link Map#containsValue} and |
| * {@code Map.toString()}. For this to perform well, {@code function} should |
| * be fast. To avoid lazy evaluation when the returned map doesn't need to be |
| * a view, copy the returned map into a new map of your choosing. |
| */ |
| public static <K, V1, V2> Map<K, V2> transformValues( |
| Map<K, V1> fromMap, Function<? super V1, V2> function) { |
| return transformEntries(fromMap, asEntryTransformer(function)); |
| } |
| |
| /** |
| * Returns a view of a sorted map where each value is transformed by a |
| * function. All other properties of the map, such as iteration order, are |
| * left intact. For example, the code: <pre> {@code |
| * |
| * SortedMap<String, Integer> map = ImmutableSortedMap.of("a", 4, "b", 9); |
| * Function<Integer, Double> sqrt = |
| * new Function<Integer, Double>() { |
| * public Double apply(Integer in) { |
| * return Math.sqrt((int) in); |
| * } |
| * }; |
| * SortedMap<String, Double> transformed = |
| * Maps.transformValues(map, sqrt); |
| * System.out.println(transformed);}</pre> |
| * |
| * ... prints {@code {a=2.0, b=3.0}}. |
| * |
| * <p>Changes in the underlying map are reflected in this view. Conversely, |
| * this view supports removal operations, and these are reflected in the |
| * underlying map. |
| * |
| * <p>It's acceptable for the underlying map to contain null keys, and even |
| * null values provided that the function is capable of accepting null input. |
| * The transformed map might contain null values, if the function sometimes |
| * gives a null result. |
| * |
| * <p>The returned map is not thread-safe or serializable, even if the |
| * underlying map is. |
| * |
| * <p>The function is applied lazily, invoked when needed. This is necessary |
| * for the returned map to be a view, but it means that the function will be |
| * applied many times for bulk operations like {@link Map#containsValue} and |
| * {@code Map.toString()}. For this to perform well, {@code function} should |
| * be fast. To avoid lazy evaluation when the returned map doesn't need to be |
| * a view, copy the returned map into a new map of your choosing. |
| * |
| * @since 11.0 |
| */ |
| public static <K, V1, V2> SortedMap<K, V2> transformValues( |
| SortedMap<K, V1> fromMap, Function<? super V1, V2> function) { |
| return transformEntries(fromMap, asEntryTransformer(function)); |
| } |
| |
| /** |
| * Returns a view of a map whose values are derived from the original map's |
| * entries. In contrast to {@link #transformValues}, this method's |
| * entry-transformation logic may depend on the key as well as the value. |
| * |
| * <p>All other properties of the transformed map, such as iteration order, |
| * are left intact. For example, the code: <pre> {@code |
| * |
| * Map<String, Boolean> options = |
| * ImmutableMap.of("verbose", true, "sort", false); |
| * EntryTransformer<String, Boolean, String> flagPrefixer = |
| * new EntryTransformer<String, Boolean, String>() { |
| * public String transformEntry(String key, Boolean value) { |
| * return value ? key : "no" + key; |
| * } |
| * }; |
| * Map<String, String> transformed = |
| * Maps.transformEntries(options, flagPrefixer); |
| * System.out.println(transformed);}</pre> |
| * |
| * ... prints {@code {verbose=verbose, sort=nosort}}. |
| * |
| * <p>Changes in the underlying map are reflected in this view. Conversely, |
| * this view supports removal operations, and these are reflected in the |
| * underlying map. |
| * |
| * <p>It's acceptable for the underlying map to contain null keys and null |
| * values provided that the transformer is capable of accepting null inputs. |
| * The transformed map might contain null values if the transformer sometimes |
| * gives a null result. |
| * |
| * <p>The returned map is not thread-safe or serializable, even if the |
| * underlying map is. |
| * |
| * <p>The transformer is applied lazily, invoked when needed. This is |
| * necessary for the returned map to be a view, but it means that the |
| * transformer will be applied many times for bulk operations like {@link |
| * Map#containsValue} and {@link Object#toString}. For this to perform well, |
| * {@code transformer} should be fast. To avoid lazy evaluation when the |
| * returned map doesn't need to be a view, copy the returned map into a new |
| * map of your choosing. |
| * |
| * <p><b>Warning:</b> This method assumes that for any instance {@code k} of |
| * {@code EntryTransformer} key type {@code K}, {@code k.equals(k2)} implies |
| * that {@code k2} is also of type {@code K}. Using an {@code |
| * EntryTransformer} key type for which this may not hold, such as {@code |
| * ArrayList}, may risk a {@code ClassCastException} when calling methods on |
| * the transformed map. |
| * |
| * @since 7.0 |
| */ |
| public static <K, V1, V2> Map<K, V2> transformEntries( |
| Map<K, V1> fromMap, |
| EntryTransformer<? super K, ? super V1, V2> transformer) { |
| if (fromMap instanceof SortedMap) { |
| return transformEntries((SortedMap<K, V1>) fromMap, transformer); |
| } |
| return new TransformedEntriesMap<K, V1, V2>(fromMap, transformer); |
| } |
| |
| /** |
| * Returns a view of a sorted map whose values are derived from the original |
| * sorted map's entries. In contrast to {@link #transformValues}, this |
| * method's entry-transformation logic may depend on the key as well as the |
| * value. |
| * |
| * <p>All other properties of the transformed map, such as iteration order, |
| * are left intact. For example, the code: <pre> {@code |
| * |
| * Map<String, Boolean> options = |
| * ImmutableSortedMap.of("verbose", true, "sort", false); |
| * EntryTransformer<String, Boolean, String> flagPrefixer = |
| * new EntryTransformer<String, Boolean, String>() { |
| * public String transformEntry(String key, Boolean value) { |
| * return value ? key : "yes" + key; |
| * } |
| * }; |
| * SortedMap<String, String> transformed = |
| * Maps.transformEntries(options, flagPrefixer); |
| * System.out.println(transformed);}</pre> |
| * |
| * ... prints {@code {sort=yessort, verbose=verbose}}. |
| * |
| * <p>Changes in the underlying map are reflected in this view. Conversely, |
| * this view supports removal operations, and these are reflected in the |
| * underlying map. |
| * |
| * <p>It's acceptable for the underlying map to contain null keys and null |
| * values provided that the transformer is capable of accepting null inputs. |
| * The transformed map might contain null values if the transformer sometimes |
| * gives a null result. |
| * |
| * <p>The returned map is not thread-safe or serializable, even if the |
| * underlying map is. |
| * |
| * <p>The transformer is applied lazily, invoked when needed. This is |
| * necessary for the returned map to be a view, but it means that the |
| * transformer will be applied many times for bulk operations like {@link |
| * Map#containsValue} and {@link Object#toString}. For this to perform well, |
| * {@code transformer} should be fast. To avoid lazy evaluation when the |
| * returned map doesn't need to be a view, copy the returned map into a new |
| * map of your choosing. |
| * |
| * <p><b>Warning:</b> This method assumes that for any instance {@code k} of |
| * {@code EntryTransformer} key type {@code K}, {@code k.equals(k2)} implies |
| * that {@code k2} is also of type {@code K}. Using an {@code |
| * EntryTransformer} key type for which this may not hold, such as {@code |
| * ArrayList}, may risk a {@code ClassCastException} when calling methods on |
| * the transformed map. |
| * |
| * @since 11.0 |
| */ |
| public static <K, V1, V2> SortedMap<K, V2> transformEntries( |
| SortedMap<K, V1> fromMap, |
| EntryTransformer<? super K, ? super V1, V2> transformer) { |
| return Platform.mapsTransformEntriesSortedMap(fromMap, transformer); |
| } |
| |
| static <K, V1, V2> SortedMap<K, V2> transformEntriesIgnoreNavigable( |
| SortedMap<K, V1> fromMap, |
| EntryTransformer<? super K, ? super V1, V2> transformer) { |
| return new TransformedEntriesSortedMap<K, V1, V2>(fromMap, transformer); |
| } |
| |
| /** |
| * A transformation of the value of a key-value pair, using both key and value |
| * as inputs. To apply the transformation to a map, use |
| * {@link Maps#transformEntries(Map, EntryTransformer)}. |
| * |
| * @param <K> the key type of the input and output entries |
| * @param <V1> the value type of the input entry |
| * @param <V2> the value type of the output entry |
| * @since 7.0 |
| */ |
| public interface EntryTransformer<K, V1, V2> { |
| /** |
| * Determines an output value based on a key-value pair. This method is |
| * <i>generally expected</i>, but not absolutely required, to have the |
| * following properties: |
| * |
| * <ul> |
| * <li>Its execution does not cause any observable side effects. |
| * <li>The computation is <i>consistent with equals</i>; that is, |
| * {@link Objects#equal Objects.equal}{@code (k1, k2) &&} |
| * {@link Objects#equal}{@code (v1, v2)} implies that {@code |
| * Objects.equal(transformer.transform(k1, v1), |
| * transformer.transform(k2, v2))}. |
| * </ul> |
| * |
| * @throws NullPointerException if the key or value is null and this |
| * transformer does not accept null arguments |
| */ |
| V2 transformEntry(@Nullable K key, @Nullable V1 value); |
| } |
| |
| /** |
| * Views a function as an entry transformer that ignores the entry key. |
| */ |
| static <K, V1, V2> EntryTransformer<K, V1, V2> |
| asEntryTransformer(final Function<? super V1, V2> function) { |
| checkNotNull(function); |
| return new EntryTransformer<K, V1, V2>() { |
| @Override |
| public V2 transformEntry(K key, V1 value) { |
| return function.apply(value); |
| } |
| }; |
| } |
| |
| static <K, V1, V2> Function<V1, V2> asValueToValueFunction( |
| final EntryTransformer<? super K, V1, V2> transformer, final K key) { |
| checkNotNull(transformer); |
| return new Function<V1, V2>() { |
| @Override |
| public V2 apply(@Nullable V1 v1) { |
| return transformer.transformEntry(key, v1); |
| } |
| }; |
| } |
| |
| /** |
| * Views an entry transformer as a function from {@code Entry} to values. |
| */ |
| static <K, V1, V2> Function<Entry<K, V1>, V2> asEntryToValueFunction( |
| final EntryTransformer<? super K, ? super V1, V2> transformer) { |
| checkNotNull(transformer); |
| return new Function<Entry<K, V1>, V2>() { |
| @Override |
| public V2 apply(Entry<K, V1> entry) { |
| return transformer.transformEntry(entry.getKey(), entry.getValue()); |
| } |
| }; |
| } |
| |
| /** |
| * Returns a view of an entry transformed by the specified transformer. |
| */ |
| static <V2, K, V1> Entry<K, V2> transformEntry( |
| final EntryTransformer<? super K, ? super V1, V2> transformer, final Entry<K, V1> entry) { |
| checkNotNull(transformer); |
| checkNotNull(entry); |
| return new AbstractMapEntry<K, V2>() { |
| @Override |
| public K getKey() { |
| return entry.getKey(); |
| } |
| |
| @Override |
| public V2 getValue() { |
| return transformer.transformEntry(entry.getKey(), entry.getValue()); |
| } |
| }; |
| } |
| |
| /** |
| * Views an entry transformer as a function from entries to entries. |
| */ |
| static <K, V1, V2> Function<Entry<K, V1>, Entry<K, V2>> asEntryToEntryFunction( |
| final EntryTransformer<? super K, ? super V1, V2> transformer) { |
| checkNotNull(transformer); |
| return new Function<Entry<K, V1>, Entry<K, V2>>() { |
| @Override |
| public Entry<K, V2> apply(final Entry<K, V1> entry) { |
| return transformEntry(transformer, entry); |
| } |
| }; |
| } |
| |
| static class TransformedEntriesMap<K, V1, V2> |
| extends ImprovedAbstractMap<K, V2> { |
| final Map<K, V1> fromMap; |
| final EntryTransformer<? super K, ? super V1, V2> transformer; |
| |
| TransformedEntriesMap( |
| Map<K, V1> fromMap, |
| EntryTransformer<? super K, ? super V1, V2> transformer) { |
| this.fromMap = checkNotNull(fromMap); |
| this.transformer = checkNotNull(transformer); |
| } |
| |
| @Override public int size() { |
| return fromMap.size(); |
| } |
| |
| @Override public boolean containsKey(Object key) { |
| return fromMap.containsKey(key); |
| } |
| |
| // safe as long as the user followed the <b>Warning</b> in the javadoc |
| @SuppressWarnings("unchecked") |
| @Override public V2 get(Object key) { |
| V1 value = fromMap.get(key); |
| return (value != null || fromMap.containsKey(key)) |
| ? transformer.transformEntry((K) key, value) |
| : null; |
| } |
| |
| // safe as long as the user followed the <b>Warning</b> in the javadoc |
| @SuppressWarnings("unchecked") |
| @Override public V2 remove(Object key) { |
| return fromMap.containsKey(key) |
| ? transformer.transformEntry((K) key, fromMap.remove(key)) |
| : null; |
| } |
| |
| @Override public void clear() { |
| fromMap.clear(); |
| } |
| |
| @Override public Set<K> keySet() { |
| return fromMap.keySet(); |
| } |
| |
| @Override |
| protected Set<Entry<K, V2>> createEntrySet() { |
| return new EntrySet<K, V2>() { |
| @Override Map<K, V2> map() { |
| return TransformedEntriesMap.this; |
| } |
| |
| @Override public Iterator<Entry<K, V2>> iterator() { |
| return Iterators.transform(fromMap.entrySet().iterator(), |
| Maps.<K, V1, V2>asEntryToEntryFunction(transformer)); |
| } |
| }; |
| } |
| } |
| |
| static class TransformedEntriesSortedMap<K, V1, V2> |
| extends TransformedEntriesMap<K, V1, V2> implements SortedMap<K, V2> { |
| |
| protected SortedMap<K, V1> fromMap() { |
| return (SortedMap<K, V1>) fromMap; |
| } |
| |
| TransformedEntriesSortedMap(SortedMap<K, V1> fromMap, |
| EntryTransformer<? super K, ? super V1, V2> transformer) { |
| super(fromMap, transformer); |
| } |
| |
| @Override public Comparator<? super K> comparator() { |
| return fromMap().comparator(); |
| } |
| |
| @Override public K firstKey() { |
| return fromMap().firstKey(); |
| } |
| |
| @Override public SortedMap<K, V2> headMap(K toKey) { |
| return transformEntries(fromMap().headMap(toKey), transformer); |
| } |
| |
| @Override public K lastKey() { |
| return fromMap().lastKey(); |
| } |
| |
| @Override public SortedMap<K, V2> subMap(K fromKey, K toKey) { |
| return transformEntries( |
| fromMap().subMap(fromKey, toKey), transformer); |
| } |
| |
| @Override public SortedMap<K, V2> tailMap(K fromKey) { |
| return transformEntries(fromMap().tailMap(fromKey), transformer); |
| } |
| } |
| |
| static <K> Predicate<Entry<K, ?>> keyPredicateOnEntries(Predicate<? super K> keyPredicate) { |
| return compose(keyPredicate, Maps.<K>keyFunction()); |
| } |
| |
| static <V> Predicate<Entry<?, V>> valuePredicateOnEntries(Predicate<? super V> valuePredicate) { |
| return compose(valuePredicate, Maps.<V>valueFunction()); |
| } |
| |
| /** |
| * Returns a map containing the mappings in {@code unfiltered} whose keys |
| * satisfy a predicate. The returned map is a live view of {@code unfiltered}; |
| * changes to one affect the other. |
| * |
| * <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code |
| * values()} views have iterators that don't support {@code remove()}, but all |
| * other methods are supported by the map and its views. When given a key that |
| * doesn't satisfy the predicate, the map's {@code put()} and {@code putAll()} |
| * methods throw an {@link IllegalArgumentException}. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called |
| * on the filtered map or its views, only mappings whose keys satisfy the |
| * filter will be removed from the underlying map. |
| * |
| * <p>The returned map isn't threadsafe or serializable, even if {@code |
| * unfiltered} is. |
| * |
| * <p>Many of the filtered map's methods, such as {@code size()}, |
| * iterate across every key/value mapping in the underlying map and determine |
| * which satisfy the filter. When a live view is <i>not</i> needed, it may be |
| * faster to copy the filtered map and use the copy. |
| * |
| * <p><b>Warning:</b> {@code keyPredicate} must be <i>consistent with |
| * equals</i>, as documented at {@link Predicate#apply}. Do not provide a |
| * predicate such as {@code Predicates.instanceOf(ArrayList.class)}, which is |
| * inconsistent with equals. |
| */ |
| public static <K, V> Map<K, V> filterKeys( |
| Map<K, V> unfiltered, final Predicate<? super K> keyPredicate) { |
| if (unfiltered instanceof SortedMap) { |
| return filterKeys((SortedMap<K, V>) unfiltered, keyPredicate); |
| } else if (unfiltered instanceof BiMap) { |
| return filterKeys((BiMap<K, V>) unfiltered, keyPredicate); |
| } |
| checkNotNull(keyPredicate); |
| Predicate<Entry<K, ?>> entryPredicate = keyPredicateOnEntries(keyPredicate); |
| return (unfiltered instanceof AbstractFilteredMap) |
| ? filterFiltered((AbstractFilteredMap<K, V>) unfiltered, entryPredicate) |
| : new FilteredKeyMap<K, V>( |
| checkNotNull(unfiltered), keyPredicate, entryPredicate); |
| } |
| |
| /** |
| * Returns a sorted map containing the mappings in {@code unfiltered} whose |
| * keys satisfy a predicate. The returned map is a live view of {@code |
| * unfiltered}; changes to one affect the other. |
| * |
| * <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code |
| * values()} views have iterators that don't support {@code remove()}, but all |
| * other methods are supported by the map and its views. When given a key that |
| * doesn't satisfy the predicate, the map's {@code put()} and {@code putAll()} |
| * methods throw an {@link IllegalArgumentException}. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called |
| * on the filtered map or its views, only mappings whose keys satisfy the |
| * filter will be removed from the underlying map. |
| * |
| * <p>The returned map isn't threadsafe or serializable, even if {@code |
| * unfiltered} is. |
| * |
| * <p>Many of the filtered map's methods, such as {@code size()}, |
| * iterate across every key/value mapping in the underlying map and determine |
| * which satisfy the filter. When a live view is <i>not</i> needed, it may be |
| * faster to copy the filtered map and use the copy. |
| * |
| * <p><b>Warning:</b> {@code keyPredicate} must be <i>consistent with |
| * equals</i>, as documented at {@link Predicate#apply}. Do not provide a |
| * predicate such as {@code Predicates.instanceOf(ArrayList.class)}, which is |
| * inconsistent with equals. |
| * |
| * @since 11.0 |
| */ |
| public static <K, V> SortedMap<K, V> filterKeys( |
| SortedMap<K, V> unfiltered, final Predicate<? super K> keyPredicate) { |
| // TODO(user): Return a subclass of Maps.FilteredKeyMap for slightly better |
| // performance. |
| return filterEntries(unfiltered, Maps.<K>keyPredicateOnEntries(keyPredicate)); |
| } |
| |
| /** |
| * Returns a bimap containing the mappings in {@code unfiltered} whose keys satisfy a predicate. |
| * The returned bimap is a live view of {@code unfiltered}; changes to one affect the other. |
| * |
| * <p>The resulting bimap's {@code keySet()}, {@code entrySet()}, and {@code values()} views have |
| * iterators that don't support {@code remove()}, but all other methods are supported by the |
| * bimap and its views. When given a key that doesn't satisfy the predicate, the bimap's {@code |
| * put()}, {@code forcePut()} and {@code putAll()} methods throw an {@link |
| * IllegalArgumentException}. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called on the filtered |
| * bimap or its views, only mappings that satisfy the filter will be removed from the underlying |
| * bimap. |
| * |
| * <p>The returned bimap isn't threadsafe or serializable, even if {@code unfiltered} is. |
| * |
| * <p>Many of the filtered bimap's methods, such as {@code size()}, iterate across every key in |
| * the underlying bimap and determine which satisfy the filter. When a live view is <i>not</i> |
| * needed, it may be faster to copy the filtered bimap and use the copy. |
| * |
| * <p><b>Warning:</b> {@code entryPredicate} must be <i>consistent with equals </i>, as |
| * documented at {@link Predicate#apply}. |
| * |
| * @since 14.0 |
| */ |
| public static <K, V> BiMap<K, V> filterKeys( |
| BiMap<K, V> unfiltered, final Predicate<? super K> keyPredicate) { |
| checkNotNull(keyPredicate); |
| return filterEntries(unfiltered, Maps.<K>keyPredicateOnEntries(keyPredicate)); |
| } |
| |
| /** |
| * Returns a map containing the mappings in {@code unfiltered} whose values |
| * satisfy a predicate. The returned map is a live view of {@code unfiltered}; |
| * changes to one affect the other. |
| * |
| * <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code |
| * values()} views have iterators that don't support {@code remove()}, but all |
| * other methods are supported by the map and its views. When given a value |
| * that doesn't satisfy the predicate, the map's {@code put()}, {@code |
| * putAll()}, and {@link Entry#setValue} methods throw an {@link |
| * IllegalArgumentException}. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called |
| * on the filtered map or its views, only mappings whose values satisfy the |
| * filter will be removed from the underlying map. |
| * |
| * <p>The returned map isn't threadsafe or serializable, even if {@code |
| * unfiltered} is. |
| * |
| * <p>Many of the filtered map's methods, such as {@code size()}, |
| * iterate across every key/value mapping in the underlying map and determine |
| * which satisfy the filter. When a live view is <i>not</i> needed, it may be |
| * faster to copy the filtered map and use the copy. |
| * |
| * <p><b>Warning:</b> {@code valuePredicate} must be <i>consistent with |
| * equals</i>, as documented at {@link Predicate#apply}. Do not provide a |
| * predicate such as {@code Predicates.instanceOf(ArrayList.class)}, which is |
| * inconsistent with equals. |
| */ |
| public static <K, V> Map<K, V> filterValues( |
| Map<K, V> unfiltered, final Predicate<? super V> valuePredicate) { |
| if (unfiltered instanceof SortedMap) { |
| return filterValues((SortedMap<K, V>) unfiltered, valuePredicate); |
| } else if (unfiltered instanceof BiMap) { |
| return filterValues((BiMap<K, V>) unfiltered, valuePredicate); |
| } |
| return filterEntries(unfiltered, Maps.<V>valuePredicateOnEntries(valuePredicate)); |
| } |
| |
| /** |
| * Returns a sorted map containing the mappings in {@code unfiltered} whose |
| * values satisfy a predicate. The returned map is a live view of {@code |
| * unfiltered}; changes to one affect the other. |
| * |
| * <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code |
| * values()} views have iterators that don't support {@code remove()}, but all |
| * other methods are supported by the map and its views. When given a value |
| * that doesn't satisfy the predicate, the map's {@code put()}, {@code |
| * putAll()}, and {@link Entry#setValue} methods throw an {@link |
| * IllegalArgumentException}. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called |
| * on the filtered map or its views, only mappings whose values satisfy the |
| * filter will be removed from the underlying map. |
| * |
| * <p>The returned map isn't threadsafe or serializable, even if {@code |
| * unfiltered} is. |
| * |
| * <p>Many of the filtered map's methods, such as {@code size()}, |
| * iterate across every key/value mapping in the underlying map and determine |
| * which satisfy the filter. When a live view is <i>not</i> needed, it may be |
| * faster to copy the filtered map and use the copy. |
| * |
| * <p><b>Warning:</b> {@code valuePredicate} must be <i>consistent with |
| * equals</i>, as documented at {@link Predicate#apply}. Do not provide a |
| * predicate such as {@code Predicates.instanceOf(ArrayList.class)}, which is |
| * inconsistent with equals. |
| * |
| * @since 11.0 |
| */ |
| public static <K, V> SortedMap<K, V> filterValues( |
| SortedMap<K, V> unfiltered, final Predicate<? super V> valuePredicate) { |
| return filterEntries(unfiltered, Maps.<V>valuePredicateOnEntries(valuePredicate)); |
| } |
| |
| /** |
| * Returns a bimap containing the mappings in {@code unfiltered} whose values satisfy a |
| * predicate. The returned bimap is a live view of {@code unfiltered}; changes to one affect the |
| * other. |
| * |
| * <p>The resulting bimap's {@code keySet()}, {@code entrySet()}, and {@code values()} views have |
| * iterators that don't support {@code remove()}, but all other methods are supported by the |
| * bimap and its views. When given a value that doesn't satisfy the predicate, the bimap's |
| * {@code put()}, {@code forcePut()} and {@code putAll()} methods throw an {@link |
| * IllegalArgumentException}. Similarly, the map's entries have a {@link Entry#setValue} method |
| * that throws an {@link IllegalArgumentException} when the provided value doesn't satisfy the |
| * predicate. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called on the filtered |
| * bimap or its views, only mappings that satisfy the filter will be removed from the underlying |
| * bimap. |
| * |
| * <p>The returned bimap isn't threadsafe or serializable, even if {@code unfiltered} is. |
| * |
| * <p>Many of the filtered bimap's methods, such as {@code size()}, iterate across every value in |
| * the underlying bimap and determine which satisfy the filter. When a live view is <i>not</i> |
| * needed, it may be faster to copy the filtered bimap and use the copy. |
| * |
| * <p><b>Warning:</b> {@code entryPredicate} must be <i>consistent with equals </i>, as |
| * documented at {@link Predicate#apply}. |
| * |
| * @since 14.0 |
| */ |
| public static <K, V> BiMap<K, V> filterValues( |
| BiMap<K, V> unfiltered, final Predicate<? super V> valuePredicate) { |
| return filterEntries(unfiltered, Maps.<V>valuePredicateOnEntries(valuePredicate)); |
| } |
| |
| /** |
| * Returns a map containing the mappings in {@code unfiltered} that satisfy a |
| * predicate. The returned map is a live view of {@code unfiltered}; changes |
| * to one affect the other. |
| * |
| * <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code |
| * values()} views have iterators that don't support {@code remove()}, but all |
| * other methods are supported by the map and its views. When given a |
| * key/value pair that doesn't satisfy the predicate, the map's {@code put()} |
| * and {@code putAll()} methods throw an {@link IllegalArgumentException}. |
| * Similarly, the map's entries have a {@link Entry#setValue} method that |
| * throws an {@link IllegalArgumentException} when the existing key and the |
| * provided value don't satisfy the predicate. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called |
| * on the filtered map or its views, only mappings that satisfy the filter |
| * will be removed from the underlying map. |
| * |
| * <p>The returned map isn't threadsafe or serializable, even if {@code |
| * unfiltered} is. |
| * |
| * <p>Many of the filtered map's methods, such as {@code size()}, |
| * iterate across every key/value mapping in the underlying map and determine |
| * which satisfy the filter. When a live view is <i>not</i> needed, it may be |
| * faster to copy the filtered map and use the copy. |
| * |
| * <p><b>Warning:</b> {@code entryPredicate} must be <i>consistent with |
| * equals</i>, as documented at {@link Predicate#apply}. |
| */ |
| public static <K, V> Map<K, V> filterEntries( |
| Map<K, V> unfiltered, Predicate<? super Entry<K, V>> entryPredicate) { |
| if (unfiltered instanceof SortedMap) { |
| return filterEntries((SortedMap<K, V>) unfiltered, entryPredicate); |
| } else if (unfiltered instanceof BiMap) { |
| return filterEntries((BiMap<K, V>) unfiltered, entryPredicate); |
| } |
| checkNotNull(entryPredicate); |
| return (unfiltered instanceof AbstractFilteredMap) |
| ? filterFiltered((AbstractFilteredMap<K, V>) unfiltered, entryPredicate) |
| : new FilteredEntryMap<K, V>(checkNotNull(unfiltered), entryPredicate); |
| } |
| |
| /** |
| * Returns a sorted map containing the mappings in {@code unfiltered} that |
| * satisfy a predicate. The returned map is a live view of {@code unfiltered}; |
| * changes to one affect the other. |
| * |
| * <p>The resulting map's {@code keySet()}, {@code entrySet()}, and {@code |
| * values()} views have iterators that don't support {@code remove()}, but all |
| * other methods are supported by the map and its views. When given a |
| * key/value pair that doesn't satisfy the predicate, the map's {@code put()} |
| * and {@code putAll()} methods throw an {@link IllegalArgumentException}. |
| * Similarly, the map's entries have a {@link Entry#setValue} method that |
| * throws an {@link IllegalArgumentException} when the existing key and the |
| * provided value don't satisfy the predicate. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called |
| * on the filtered map or its views, only mappings that satisfy the filter |
| * will be removed from the underlying map. |
| * |
| * <p>The returned map isn't threadsafe or serializable, even if {@code |
| * unfiltered} is. |
| * |
| * <p>Many of the filtered map's methods, such as {@code size()}, |
| * iterate across every key/value mapping in the underlying map and determine |
| * which satisfy the filter. When a live view is <i>not</i> needed, it may be |
| * faster to copy the filtered map and use the copy. |
| * |
| * <p><b>Warning:</b> {@code entryPredicate} must be <i>consistent with |
| * equals</i>, as documented at {@link Predicate#apply}. |
| * |
| * @since 11.0 |
| */ |
| public static <K, V> SortedMap<K, V> filterEntries( |
| SortedMap<K, V> unfiltered, |
| Predicate<? super Entry<K, V>> entryPredicate) { |
| return Platform.mapsFilterSortedMap(unfiltered, entryPredicate); |
| } |
| |
| static <K, V> SortedMap<K, V> filterSortedIgnoreNavigable( |
| SortedMap<K, V> unfiltered, |
| Predicate<? super Entry<K, V>> entryPredicate) { |
| checkNotNull(entryPredicate); |
| return (unfiltered instanceof FilteredEntrySortedMap) |
| ? filterFiltered((FilteredEntrySortedMap<K, V>) unfiltered, entryPredicate) |
| : new FilteredEntrySortedMap<K, V>(checkNotNull(unfiltered), entryPredicate); |
| } |
| |
| /** |
| * Returns a bimap containing the mappings in {@code unfiltered} that satisfy a predicate. The |
| * returned bimap is a live view of {@code unfiltered}; changes to one affect the other. |
| * |
| * <p>The resulting bimap's {@code keySet()}, {@code entrySet()}, and {@code values()} views have |
| * iterators that don't support {@code remove()}, but all other methods are supported by the bimap |
| * and its views. When given a key/value pair that doesn't satisfy the predicate, the bimap's |
| * {@code put()}, {@code forcePut()} and {@code putAll()} methods throw an |
| * {@link IllegalArgumentException}. Similarly, the map's entries have an {@link Entry#setValue} |
| * method that throws an {@link IllegalArgumentException} when the existing key and the provided |
| * value don't satisfy the predicate. |
| * |
| * <p>When methods such as {@code removeAll()} and {@code clear()} are called on the filtered |
| * bimap or its views, only mappings that satisfy the filter will be removed from the underlying |
| * bimap. |
| * |
| * <p>The returned bimap isn't threadsafe or serializable, even if {@code unfiltered} is. |
| * |
| * <p>Many of the filtered bimap's methods, such as {@code size()}, iterate across every |
| * key/value mapping in the underlying bimap and determine which satisfy the filter. When a live |
| * view is <i>not</i> needed, it may be faster to copy the filtered bimap and use the copy. |
| * |
| * <p><b>Warning:</b> {@code entryPredicate} must be <i>consistent with equals </i>, as |
| * documented at {@link Predicate#apply}. |
| * |
| * @since 14.0 |
| */ |
| public static <K, V> BiMap<K, V> filterEntries( |
| BiMap<K, V> unfiltered, Predicate<? super Entry<K, V>> entryPredicate) { |
| checkNotNull(unfiltered); |
| checkNotNull(entryPredicate); |
| return (unfiltered instanceof FilteredEntryBiMap) |
| ? filterFiltered((FilteredEntryBiMap<K, V>) unfiltered, entryPredicate) |
| : new FilteredEntryBiMap<K, V>(unfiltered, entryPredicate); |
| } |
| |
| /** |
| * Support {@code clear()}, {@code removeAll()}, and {@code retainAll()} when |
| * filtering a filtered map. |
| */ |
| private static <K, V> Map<K, V> filterFiltered(AbstractFilteredMap<K, V> map, |
| Predicate<? super Entry<K, V>> entryPredicate) { |
| return new FilteredEntryMap<K, V>(map.unfiltered, |
| Predicates.<Entry<K, V>>and(map.predicate, entryPredicate)); |
| } |
| |
| private abstract static class AbstractFilteredMap<K, V> |
| extends ImprovedAbstractMap<K, V> { |
| final Map<K, V> unfiltered; |
| final Predicate<? super Entry<K, V>> predicate; |
| |
| AbstractFilteredMap( |
| Map<K, V> unfiltered, Predicate<? super Entry<K, V>> predicate) { |
| this.unfiltered = unfiltered; |
| this.predicate = predicate; |
| } |
| |
| boolean apply(@Nullable Object key, @Nullable V value) { |
| // This method is called only when the key is in the map, implying that |
| // key is a K. |
| @SuppressWarnings("unchecked") |
| K k = (K) key; |
| return predicate.apply(Maps.immutableEntry(k, value)); |
| } |
| |
| @Override public V put(K key, V value) { |
| checkArgument(apply(key, value)); |
| return unfiltered.put(key, value); |
| } |
| |
| @Override public void putAll(Map<? extends K, ? extends V> map) { |
| for (Entry<? extends K, ? extends V> entry : map.entrySet()) { |
| checkArgument(apply(entry.getKey(), entry.getValue())); |
| } |
| unfiltered.putAll(map); |
| } |
| |
| @Override public boolean containsKey(Object key) { |
| return unfiltered.containsKey(key) && apply(key, unfiltered.get(key)); |
| } |
| |
| @Override public V get(Object key) { |
| V value = unfiltered.get(key); |
| return ((value != null) && apply(key, value)) ? value : null; |
| } |
| |
| @Override public boolean isEmpty() { |
| return entrySet().isEmpty(); |
| } |
| |
| @Override public V remove(Object key) { |
| return containsKey(key) ? unfiltered.remove(key) : null; |
| } |
| |
| @Override |
| Collection<V> createValues() { |
| return new FilteredMapValues<K, V>(this, unfiltered, predicate); |
| } |
| } |
| |
| private static final class FilteredMapValues<K, V> extends Maps.Values<K, V> { |
| Map<K, V> unfiltered; |
| Predicate<? super Entry<K, V>> predicate; |
| |
| FilteredMapValues(Map<K, V> filteredMap, Map<K, V> unfiltered, |
| Predicate<? super Entry<K, V>> predicate) { |
| super(filteredMap); |
| this.unfiltered = unfiltered; |
| this.predicate = predicate; |
| } |
| |
| @Override public boolean remove(Object o) { |
| return Iterables.removeFirstMatching(unfiltered.entrySet(), |
| Predicates.<Entry<K, V>>and(predicate, Maps.<V>valuePredicateOnEntries(equalTo(o)))) |
| != null; |
| } |
| |
| private boolean removeIf(Predicate<? super V> valuePredicate) { |
| return Iterables.removeIf(unfiltered.entrySet(), Predicates.<Entry<K, V>>and( |
| predicate, Maps.<V>valuePredicateOnEntries(valuePredicate))); |
| } |
| |
| @Override public boolean removeAll(Collection<?> collection) { |
| return removeIf(in(collection)); |
| } |
| |
| @Override public boolean retainAll(Collection<?> collection) { |
| return removeIf(not(in(collection))); |
| } |
| |
| @Override public Object[] toArray() { |
| // creating an ArrayList so filtering happens once |
| return Lists.newArrayList(iterator()).toArray(); |
| } |
| |
| @Override public <T> T[] toArray(T[] array) { |
| return Lists.newArrayList(iterator()).toArray(array); |
| } |
| } |
| |
| private static class FilteredKeyMap<K, V> extends AbstractFilteredMap<K, V> { |
| Predicate<? super K> keyPredicate; |
| |
| FilteredKeyMap(Map<K, V> unfiltered, Predicate<? super K> keyPredicate, |
| Predicate<? super Entry<K, V>> entryPredicate) { |
| super(unfiltered, entryPredicate); |
| this.keyPredicate = keyPredicate; |
| } |
| |
| @Override |
| protected Set<Entry<K, V>> createEntrySet() { |
| return Sets.filter(unfiltered.entrySet(), predicate); |
| } |
| |
| @Override |
| Set<K> createKeySet() { |
| return Sets.filter(unfiltered.keySet(), keyPredicate); |
| } |
| |
| // The cast is called only when the key is in the unfiltered map, implying |
| // that key is a K. |
| @Override |
| @SuppressWarnings("unchecked") |
| public boolean containsKey(Object key) { |
| return unfiltered.containsKey(key) && keyPredicate.apply((K) key); |
| } |
| } |
| |
| static class FilteredEntryMap<K, V> extends AbstractFilteredMap<K, V> { |
| /** |
| * Entries in this set satisfy the predicate, but they don't validate the |
| * input to {@code Entry.setValue()}. |
| */ |
| final Set<Entry<K, V>> filteredEntrySet; |
| |
| FilteredEntryMap( |
| Map<K, V> unfiltered, Predicate<? super Entry<K, V>> entryPredicate) { |
| super(unfiltered, entryPredicate); |
| filteredEntrySet = Sets.filter(unfiltered.entrySet(), predicate); |
| } |
| |
| @Override |
| protected Set<Entry<K, V>> createEntrySet() { |
| return new EntrySet(); |
| } |
| |
| private class EntrySet extends ForwardingSet<Entry<K, V>> { |
| @Override protected Set<Entry<K, V>> delegate() { |
| return filteredEntrySet; |
| } |
| |
| @Override public Iterator<Entry<K, V>> iterator() { |
| return new TransformedIterator<Entry<K, V>, Entry<K, V>>(filteredEntrySet.iterator()) { |
| @Override |
| Entry<K, V> transform(final Entry<K, V> entry) { |
| return new ForwardingMapEntry<K, V>() { |
| @Override |
| protected Entry<K, V> delegate() { |
| return entry; |
| } |
| |
| @Override |
| public V setValue(V newValue) { |
| checkArgument(apply(getKey(), newValue)); |
| return super.setValue(newValue); |
| } |
| }; |
| } |
| }; |
| } |
| } |
| |
| @Override |
| Set<K> createKeySet() { |
| return new KeySet(); |
| } |
| |
| class KeySet extends Maps.KeySet<K, V> { |
| KeySet() { |
| super(FilteredEntryMap.this); |
| } |
| |
| @Override public boolean remove(Object o) { |
| if (containsKey(o)) { |
| unfiltered.remove(o); |
| return true; |
| } |
| return false; |
| } |
| |
| private boolean removeIf(Predicate<? super K> keyPredicate) { |
| return Iterables.removeIf(unfiltered.entrySet(), Predicates.<Entry<K, V>>and( |
| predicate, Maps.<K>keyPredicateOnEntries(keyPredicate))); |
| } |
| |
| @Override |
| public boolean removeAll(Collection<?> c) { |
| return removeIf(in(c)); |
| } |
| |
| @Override |
| public boolean retainAll(Collection<?> c) { |
| return removeIf(not(in(c))); |
| } |
| |
| @Override public Object[] toArray() { |
| // creating an ArrayList so filtering happens once |
| return Lists.newArrayList(iterator()).toArray(); |
| } |
| |
| @Override public <T> T[] toArray(T[] array) { |
| return Lists.newArrayList(iterator()).toArray(array); |
| } |
| } |
| } |
| |
| /** |
| * Support {@code clear()}, {@code removeAll()}, and {@code retainAll()} when |
| * filtering a filtered sorted map. |
| */ |
| private static <K, V> SortedMap<K, V> filterFiltered( |
| FilteredEntrySortedMap<K, V> map, |
| Predicate<? super Entry<K, V>> entryPredicate) { |
| Predicate<Entry<K, V>> predicate |
| = Predicates.and(map.predicate, entryPredicate); |
| return new FilteredEntrySortedMap<K, V>(map.sortedMap(), predicate); |
| } |
| |
| private static class FilteredEntrySortedMap<K, V> |
| extends FilteredEntryMap<K, V> implements SortedMap<K, V> { |
| |
| FilteredEntrySortedMap(SortedMap<K, V> unfiltered, |
| Predicate<? super Entry<K, V>> entryPredicate) { |
| super(unfiltered, entryPredicate); |
| } |
| |
| SortedMap<K, V> sortedMap() { |
| return (SortedMap<K, V>) unfiltered; |
| } |
| |
| @Override public SortedSet<K> keySet() { |
| return (SortedSet<K>) super.keySet(); |
| } |
| |
| @Override |
| SortedSet<K> createKeySet() { |
| return new SortedKeySet(); |
| } |
| |
| class SortedKeySet extends KeySet implements SortedSet<K> { |
| @Override |
| public Comparator<? super K> comparator() { |
| return sortedMap().comparator(); |
| } |
| |
| @Override |
| public SortedSet<K> subSet(K fromElement, K toElement) { |
| return (SortedSet<K>) subMap(fromElement, toElement).keySet(); |
| } |
| |
| @Override |
| public SortedSet<K> headSet(K toElement) { |
| return (SortedSet<K>) headMap(toElement).keySet(); |
| } |
| |
| @Override |
| public SortedSet<K> tailSet(K fromElement) { |
| return (SortedSet<K>) tailMap(fromElement).keySet(); |
| } |
| |
| @Override |
| public K first() { |
| return firstKey(); |
| } |
| |
| @Override |
| public K last() { |
| return lastKey(); |
| } |
| } |
| |
| @Override public Comparator<? super K> comparator() { |
| return sortedMap().comparator(); |
| } |
| |
| @Override public K firstKey() { |
| // correctly throws NoSuchElementException when filtered map is empty. |
| return keySet().iterator().next(); |
| } |
| |
| @Override public K lastKey() { |
| SortedMap<K, V> headMap = sortedMap(); |
| while (true) { |
| // correctly throws NoSuchElementException when filtered map is empty. |
| K key = headMap.lastKey(); |
| if (apply(key, unfiltered.get(key))) { |
| return key; |
| } |
| headMap = sortedMap().headMap(key); |
| } |
| } |
| |
| @Override public SortedMap<K, V> headMap(K toKey) { |
| return new FilteredEntrySortedMap<K, V>(sortedMap().headMap(toKey), predicate); |
| } |
| |
| @Override public SortedMap<K, V> subMap(K fromKey, K toKey) { |
| return new FilteredEntrySortedMap<K, V>( |
| sortedMap().subMap(fromKey, toKey), predicate); |
| } |
| |
| @Override public SortedMap<K, V> tailMap(K fromKey) { |
| return new FilteredEntrySortedMap<K, V>( |
| sortedMap().tailMap(fromKey), predicate); |
| } |
| } |
| |
| /** |
| * Support {@code clear()}, {@code removeAll()}, and {@code retainAll()} when |
| * filtering a filtered map. |
| */ |
| private static <K, V> BiMap<K, V> filterFiltered( |
| FilteredEntryBiMap<K, V> map, Predicate<? super Entry<K, V>> entryPredicate) { |
| Predicate<Entry<K, V>> predicate = Predicates.and(map.predicate, entryPredicate); |
| return new FilteredEntryBiMap<K, V>(map.unfiltered(), predicate); |
| } |
| |
| static final class FilteredEntryBiMap<K, V> extends FilteredEntryMap<K, V> |
| implements BiMap<K, V> { |
| private final BiMap<V, K> inverse; |
| |
| private static <K, V> Predicate<Entry<V, K>> inversePredicate( |
| final Predicate<? super Entry<K, V>> forwardPredicate) { |
| return new Predicate<Entry<V, K>>() { |
| @Override |
| public boolean apply(Entry<V, K> input) { |
| return forwardPredicate.apply( |
| Maps.immutableEntry(input.getValue(), input.getKey())); |
| } |
| }; |
| } |
| |
| FilteredEntryBiMap(BiMap<K, V> delegate, |
| Predicate<? super Entry<K, V>> predicate) { |
| super(delegate, predicate); |
| this.inverse = new FilteredEntryBiMap<V, K>( |
| delegate.inverse(), inversePredicate(predicate), this); |
| } |
| |
| private FilteredEntryBiMap( |
| BiMap<K, V> delegate, Predicate<? super Entry<K, V>> predicate, |
| BiMap<V, K> inverse) { |
| super(delegate, predicate); |
| this.inverse = inverse; |
| } |
| |
| BiMap<K, V> unfiltered() { |
| return (BiMap<K, V>) unfiltered; |
| } |
| |
| @Override |
| public V forcePut(@Nullable K key, @Nullable V value) { |
| checkArgument(apply(key, value)); |
| return unfiltered().forcePut(key, value); |
| } |
| |
| @Override |
| public BiMap<V, K> inverse() { |
| return inverse; |
| } |
| |
| @Override |
| public Set<V> values() { |
| return inverse.keySet(); |
| } |
| } |
| |
| @Nullable private static <K, V> Entry<K, V> unmodifiableOrNull(@Nullable Entry<K, V> entry) { |
| return (entry == null) ? null : Maps.unmodifiableEntry(entry); |
| } |
| |
| /** |
| * {@code AbstractMap} extension that implements {@link #isEmpty()} as {@code |
| * entrySet().isEmpty()} instead of {@code size() == 0} to speed up |
| * implementations where {@code size()} is O(n), and it delegates the {@code |
| * isEmpty()} methods of its key set and value collection to this |
| * implementation. |
| */ |
| @GwtCompatible |
| abstract static class ImprovedAbstractMap<K, V> extends AbstractMap<K, V> { |
| /** |
| * Creates the entry set to be returned by {@link #entrySet()}. This method |
| * is invoked at most once on a given map, at the time when {@code entrySet} |
| * is first called. |
| */ |
| abstract Set<Entry<K, V>> createEntrySet(); |
| |
| private transient Set<Entry<K, V>> entrySet; |
| |
| @Override public Set<Entry<K, V>> entrySet() { |
| Set<Entry<K, V>> result = entrySet; |
| return (result == null) ? entrySet = createEntrySet() : result; |
| } |
| |
| private transient Set<K> keySet; |
| |
| @Override public Set<K> keySet() { |
| Set<K> result = keySet; |
| return (result == null) ? keySet = createKeySet() : result; |
| } |
| |
| Set<K> createKeySet() { |
| return new KeySet<K, V>(this); |
| } |
| |
| private transient Collection<V> values; |
| |
| @Override public Collection<V> values() { |
| Collection<V> result = values; |
| return (result == null) ? values = createValues() : result; |
| } |
| |
| Collection<V> createValues() { |
| return new Values<K, V>(this); |
| } |
| } |
| |
| /** |
| * Delegates to {@link Map#get}. Returns {@code null} on {@code |
| * ClassCastException} and {@code NullPointerException}. |
| */ |
| static <V> V safeGet(Map<?, V> map, @Nullable Object key) { |
| checkNotNull(map); |
| try { |
| return map.get(key); |
| } catch (ClassCastException e) { |
| return null; |
| } catch (NullPointerException e) { |
| return null; |
| } |
| } |
| |
| /** |
| * Delegates to {@link Map#containsKey}. Returns {@code false} on {@code |
| * ClassCastException} and {@code NullPointerException}. |
| */ |
| static boolean safeContainsKey(Map<?, ?> map, Object key) { |
| checkNotNull(map); |
| try { |
| return map.containsKey(key); |
| } catch (ClassCastException e) { |
| return false; |
| } catch (NullPointerException e) { |
| return false; |
| } |
| } |
| |
| /** |
| * Delegates to {@link Map#remove}. Returns {@code null} on {@code |
| * ClassCastException} and {@code NullPointerException}. |
| */ |
| static <V> V safeRemove(Map<?, V> map, Object key) { |
| checkNotNull(map); |
| try { |
| return map.remove(key); |
| } catch (ClassCastException e) { |
| return null; |
| } catch (NullPointerException e) { |
| return null; |
| } |
| } |
| |
| /** |
| * An admittedly inefficient implementation of {@link Map#containsKey}. |
| */ |
| static boolean containsKeyImpl(Map<?, ?> map, @Nullable Object key) { |
| return Iterators.contains(keyIterator(map.entrySet().iterator()), key); |
| } |
| |
| /** |
| * An implementation of {@link Map#containsValue}. |
| */ |
| static boolean containsValueImpl(Map<?, ?> map, @Nullable Object value) { |
| return Iterators.contains(valueIterator(map.entrySet().iterator()), value); |
| } |
| |
| /** |
| * Implements {@code Collection.contains} safely for forwarding collections of |
| * map entries. If {@code o} is an instance of {@code Map.Entry}, it is |
| * wrapped using {@link #unmodifiableEntry} to protect against a possible |
| * nefarious equals method. |
| * |
| * <p>Note that {@code c} is the backing (delegate) collection, rather than |
| * the forwarding collection. |
| * |
| * @param c the delegate (unwrapped) collection of map entries |
| * @param o the object that might be contained in {@code c} |
| * @return {@code true} if {@code c} contains {@code o} |
| */ |
| static <K, V> boolean containsEntryImpl(Collection<Entry<K, V>> c, Object o) { |
| if (!(o instanceof Entry)) { |
| return false; |
| } |
| return c.contains(unmodifiableEntry((Entry<?, ?>) o)); |
| } |
| |
| /** |
| * Implements {@code Collection.remove} safely for forwarding collections of |
| * map entries. If {@code o} is an instance of {@code Map.Entry}, it is |
| * wrapped using {@link #unmodifiableEntry} to protect against a possible |
| * nefarious equals method. |
| * |
| * <p>Note that {@code c} is backing (delegate) collection, rather than the |
| * forwarding collection. |
| * |
| * @param c the delegate (unwrapped) collection of map entries |
| * @param o the object to remove from {@code c} |
| * @return {@code true} if {@code c} was changed |
| */ |
| static <K, V> boolean removeEntryImpl(Collection<Entry<K, V>> c, Object o) { |
| if (!(o instanceof Entry)) { |
| return false; |
| } |
| return c.remove(unmodifiableEntry((Entry<?, ?>) o)); |
| } |
| |
| /** |
| * An implementation of {@link Map#equals}. |
| */ |
| static boolean equalsImpl(Map<?, ?> map, Object object) { |
| if (map == object) { |
| return true; |
| } else if (object instanceof Map) { |
| Map<?, ?> o = (Map<?, ?>) object; |
| return map.entrySet().equals(o.entrySet()); |
| } |
| return false; |
| } |
| |
| static final MapJoiner STANDARD_JOINER = |
| Collections2.STANDARD_JOINER.withKeyValueSeparator("="); |
| |
| /** |
| * An implementation of {@link Map#toString}. |
| */ |
| static String toStringImpl(Map<?, ?> map) { |
| StringBuilder sb |
| = Collections2.newStringBuilderForCollection(map.size()).append('{'); |
| STANDARD_JOINER.appendTo(sb, map); |
| return sb.append('}').toString(); |
| } |
| |
| /** |
| * An implementation of {@link Map#putAll}. |
| */ |
| static <K, V> void putAllImpl( |
| Map<K, V> self, Map<? extends K, ? extends V> map) { |
| for (Map.Entry<? extends K, ? extends V> entry : map.entrySet()) { |
| self.put(entry.getKey(), entry.getValue()); |
| } |
| } |
| |
| static class KeySet<K, V> extends Sets.ImprovedAbstractSet<K> { |
| final Map<K, V> map; |
| |
| KeySet(Map<K, V> map) { |
| this.map = checkNotNull(map); |
| } |
| |
| Map<K, V> map() { |
| return map; |
| } |
| |
| @Override public Iterator<K> iterator() { |
| return keyIterator(map().entrySet().iterator()); |
| } |
| |
| @Override public int size() { |
| return map().size(); |
| } |
| |
| @Override public boolean isEmpty() { |
| return map().isEmpty(); |
| } |
| |
| @Override public boolean contains(Object o) { |
| return map().containsKey(o); |
| } |
| |
| @Override public boolean remove(Object o) { |
| if (contains(o)) { |
| map().remove(o); |
| return true; |
| } |
| return false; |
| } |
| |
| @Override public void clear() { |
| map().clear(); |
| } |
| } |
| |
| @Nullable |
| static <K> K keyOrNull(@Nullable Entry<K, ?> entry) { |
| return (entry == null) ? null : entry.getKey(); |
| } |
| |
| @Nullable |
| static <V> V valueOrNull(@Nullable Entry<?, V> entry) { |
| return (entry == null) ? null : entry.getValue(); |
| } |
| |
| static class SortedKeySet<K, V> extends KeySet<K, V> implements SortedSet<K> { |
| SortedKeySet(SortedMap<K, V> map) { |
| super(map); |
| } |
| |
| @Override |
| SortedMap<K, V> map() { |
| return (SortedMap<K, V>) super.map(); |
| } |
| |
| @Override |
| public Comparator<? super K> comparator() { |
| return map().comparator(); |
| } |
| |
| @Override |
| public SortedSet<K> subSet(K fromElement, K toElement) { |
| return new SortedKeySet<K, V>(map().subMap(fromElement, toElement)); |
| } |
| |
| @Override |
| public SortedSet<K> headSet(K toElement) { |
| return new SortedKeySet<K, V>(map().headMap(toElement)); |
| } |
| |
| @Override |
| public SortedSet<K> tailSet(K fromElement) { |
| return new SortedKeySet<K, V>(map().tailMap(fromElement)); |
| } |
| |
| @Override |
| public K first() { |
| return map().firstKey(); |
| } |
| |
| @Override |
| public K last() { |
| return map().lastKey(); |
| } |
| } |
| |
| static class Values<K, V> extends AbstractCollection<V> { |
| final Map<K, V> map; |
| |
| Values(Map<K, V> map) { |
| this.map = checkNotNull(map); |
| } |
| |
| final Map<K, V> map() { |
| return map; |
| } |
| |
| @Override public Iterator<V> iterator() { |
| return valueIterator(map().entrySet().iterator()); |
| } |
| |
| @Override public boolean remove(Object o) { |
| try { |
| return super.remove(o); |
| } catch (UnsupportedOperationException e) { |
| for (Entry<K, V> entry : map().entrySet()) { |
| if (Objects.equal(o, entry.getValue())) { |
| map().remove(entry.getKey()); |
| return true; |
| } |
| } |
| return false; |
| } |
| } |
| |
| @Override public boolean removeAll(Collection<?> c) { |
| try { |
| return super.removeAll(checkNotNull(c)); |
| } catch (UnsupportedOperationException e) { |
| Set<K> toRemove = Sets.newHashSet(); |
| for (Entry<K, V> entry : map().entrySet()) { |
| if (c.contains(entry.getValue())) { |
| toRemove.add(entry.getKey()); |
| } |
| } |
| return map().keySet().removeAll(toRemove); |
| } |
| } |
| |
| @Override public boolean retainAll(Collection<?> c) { |
| try { |
| return super.retainAll(checkNotNull(c)); |
| } catch (UnsupportedOperationException e) { |
| Set<K> toRetain = Sets.newHashSet(); |
| for (Entry<K, V> entry : map().entrySet()) { |
| if (c.contains(entry.getValue())) { |
| toRetain.add(entry.getKey()); |
| } |
| } |
| return map().keySet().retainAll(toRetain); |
| } |
| } |
| |
| @Override public int size() { |
| return map().size(); |
| } |
| |
| @Override public boolean isEmpty() { |
| return map().isEmpty(); |
| } |
| |
| @Override public boolean contains(@Nullable Object o) { |
| return map().containsValue(o); |
| } |
| |
| @Override public void clear() { |
| map().clear(); |
| } |
| } |
| |
| abstract static class EntrySet<K, V> |
| extends Sets.ImprovedAbstractSet<Entry<K, V>> { |
| abstract Map<K, V> map(); |
| |
| @Override public int size() { |
| return map().size(); |
| } |
| |
| @Override public void clear() { |
| map().clear(); |
| } |
| |
| @Override public boolean contains(Object o) { |
| if (o instanceof Entry) { |
| Entry<?, ?> entry = (Entry<?, ?>) o; |
| Object key = entry.getKey(); |
| V value = Maps.safeGet(map(), key); |
| return Objects.equal(value, entry.getValue()) |
| && (value != null || map().containsKey(key)); |
| } |
| return false; |
| } |
| |
| @Override public boolean isEmpty() { |
| return map().isEmpty(); |
| } |
| |
| @Override public boolean remove(Object o) { |
| if (contains(o)) { |
| Entry<?, ?> entry = (Entry<?, ?>) o; |
| return map().keySet().remove(entry.getKey()); |
| } |
| return false; |
| } |
| |
| @Override public boolean removeAll(Collection<?> c) { |
| try { |
| return super.removeAll(checkNotNull(c)); |
| } catch (UnsupportedOperationException e) { |
| // if the iterators don't support remove |
| return Sets.removeAllImpl(this, c.iterator()); |
| } |
| } |
| |
| @Override public boolean retainAll(Collection<?> c) { |
| try { |
| return super.retainAll(checkNotNull(c)); |
| } catch (UnsupportedOperationException e) { |
| // if the iterators don't support remove |
| Set<Object> keys = Sets.newHashSetWithExpectedSize(c.size()); |
| for (Object o : c) { |
| if (contains(o)) { |
| Entry<?, ?> entry = (Entry<?, ?>) o; |
| keys.add(entry.getKey()); |
| } |
| } |
| return map().keySet().retainAll(keys); |
| } |
| } |
| } |
| } |