FJIterate { public static <K, V> MutableMultimap<K, V> groupBy( Iterable<V> iterable, Function<? super V, ? extends K> function) { return FJIterate.groupBy(iterable, function, FJIterate.DEFAULT_MIN_FORK_SIZE, FJIterate.FORK_JOIN_POOL); } private  FJIterate(); static void forEachWithIndex(
            Iterable<T> iterable,
            ObjectIntProcedure<? super T> procedure); static void forEachWithIndex(
            Iterable<T> iterable,
            PT procedure,
            ForkJoinPool executor); static void forEachWithIndex(
            Iterable<T> iterable,
            PT procedure,
            int minForkSize,
            int taskCount); static void forEachWithIndex(
            Iterable<T> iterable,
            ObjectIntProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            ForkJoinPool executor); static void forEachWithIndex(
            Iterable<T> iterable,
            ObjectIntProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            int minForkSize,
            int taskCount); static void forEachWithIndex(
            Iterable<T> iterable,
            ObjectIntProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            int minForkSize,
            int taskCount,
            ForkJoinPool executor); static void forEachWithIndexInListOnExecutor(
            List<T> list,
            ObjectIntProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            int minForkSize,
            int taskCount,
            ForkJoinPool executor); static void forEach(Iterable<T> iterable, Procedure<? super T> procedure); static void forEach(Iterable<T> iterable, Procedure<? super T> procedure, int batchSize); static void forEach(Iterable<T> iterable, Procedure<? super T> procedure, int batchSize, ForkJoinPool executor); static void forEach(
            Iterable<T> iterable,
            PT procedure,
            ForkJoinPool executor); static void forEach(
            Iterable<T> iterable,
            PT procedure,
            int minForkSize,
            int taskCount); static void forEach(
            Iterable<T> iterable,
            PT procedure,
            int minForkSize,
            int taskCount,
            ForkJoinPool executor); static void forEach(
            Iterable<T> iterable,
            ProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            ForkJoinPool executor); static void forEach(
            Iterable<T> iterable,
            ProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner); static void forEach(
            Iterable<T> iterable,
            ProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            int batchSize); static void forEach(
            Iterable<T> iterable,
            ProcedureFactory<PT> blockFactory,
            Combiner<PT> combiner,
            int batchSize,
            ForkJoinPool executor); static void forEach(
            Iterable<T> iterable,
            ProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            int minForkSize,
            int taskCount); static void forEach(
            Iterable<T> iterable,
            ProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            int minForkSize,
            int taskCount,
            ForkJoinPool executor); static void forEachInListOnExecutor(
            List<T> list,
            ProcedureFactory<PT> procedureFactory,
            Combiner<PT> combiner,
            int minForkSize,
            int taskCount,
            ForkJoinPool executor); static void forEachInBatchWithExecutor(
            BatchIterable<T> batchIterable,
            ProcedureFactory<PT> procedureFactory, Combiner<PT> combiner, int minForkSize, int taskCount,
            ForkJoinPool executor); static Collection<T> select(
            Iterable<T> iterable,
            Predicate<? super T> predicate); static Collection<T> select(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            boolean allowReorderedResult); static R select(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            R target,
            boolean allowReorderedResult); static R select(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            R target,
            int batchSize,
            ForkJoinPool executor,
            boolean allowReorderedResult); static Collection<T> reject(
            Iterable<T> iterable,
            Predicate<? super T> predicate); static Collection<T> reject(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            boolean allowReorderedResult); static R reject(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            R target,
            boolean allowReorderedResult); static R reject(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            R target,
            int batchSize,
            ForkJoinPool executor,
            boolean allowReorderedResult); static int count(Iterable<T> iterable, Predicate<? super T> predicate); static int count(Iterable<T> iterable, Predicate<? super T> predicate, int batchSize, ForkJoinPool executor); static Collection<V> collect(
            Iterable<T> iterable,
            Function<? super T, V> function); static Collection<V> collect(
            Iterable<T> iterable,
            Function<? super T, V> function,
            boolean allowReorderedResult); static R collect(
            Iterable<T> iterable,
            Function<? super T, V> function,
            R target,
            boolean allowReorderedResult); static R collect(
            Iterable<T> iterable,
            Function<? super T, V> function,
            R target,
            int batchSize,
            ForkJoinPool executor,
            boolean allowReorderedResult); static Collection<V> flatCollect(
            Iterable<T> iterable,
            Function<? super T, ? extends Iterable<V>> function); static Collection<V> flatCollect(
            Iterable<T> iterable,
            Function<? super T, ? extends Iterable<V>> function,
            boolean allowReorderedResult); static R flatCollect(
            Iterable<T> iterable,
            Function<? super T, ? extends Iterable<V>> function,
            R target,
            boolean allowReorderedResult); static R flatCollect(
            Iterable<T> iterable,
            Function<? super T, ? extends Iterable<V>> function,
            R target,
            int batchSize,
            ForkJoinPool executor,
            boolean allowReorderedResult); static Collection<V> collectIf(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            Function<? super T, V> function); static Collection<V> collectIf(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            Function<? super T, V> function,
            boolean allowReorderedResult); static R collectIf(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            Function<? super T, V> function,
            R target,
            boolean allowReorderedResult); static R collectIf(
            Iterable<T> iterable,
            Predicate<? super T> predicate,
            Function<? super T, V> function,
            R target,
            int batchSize,
            ForkJoinPool executor,
            boolean allowReorderedResult); static MutableMap<K, V> aggregateBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Function2<? super V, ? super T, ? extends V> nonMutatingAggregator); static R aggregateBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Function2<? super V, ? super T, ? extends V> nonMutatingAggregator,
            R mutableMap); static MutableMap<K, V> aggregateBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Function2<? super V, ? super T, ? extends V> nonMutatingAggregator,
            int batchSize); static R aggregateBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Function2<? super V, ? super T, ? extends V> nonMutatingAggregator,
            R mutableMap,
            int batchSize); static MutableMap<K, V> aggregateBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Function2<? super V, ? super T, ? extends V> nonMutatingAggregator,
            int batchSize,
            ForkJoinPool executor); static R aggregateBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Function2<? super V, ? super T, ? extends V> nonMutatingAggregator,
            R mutableMap,
            int batchSize,
            ForkJoinPool executor); static MutableMap<K, V> aggregateInPlaceBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Procedure2<? super V, ? super T> mutatingAggregator); static R aggregateInPlaceBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Procedure2<? super V, ? super T> mutatingAggregator,
            R mutableMap); static MutableMap<K, V> aggregateInPlaceBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Procedure2<? super V, ? super T> mutatingAggregator,
            int batchSize); static R aggregateInPlaceBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Procedure2<? super V, ? super T> mutatingAggregator,
            R mutableMap,
            int batchSize); static MutableMap<K, V> aggregateInPlaceBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Procedure2<? super V, ? super T> mutatingAggregator,
            int batchSize,
            ForkJoinPool executor); static R aggregateInPlaceBy(
            Iterable<T> iterable,
            Function<? super T, ? extends K> groupBy,
            Function0<? extends V> zeroValueFactory,
            Procedure2<? super V, ? super T> mutatingAggregator,
            R mutableMap,
            int batchSize,
            ForkJoinPool executor); static MutableMultimap<K, V> groupBy(
            Iterable<V> iterable,
            Function<? super V, ? extends K> function); static MutableMultimap<K, V> groupBy(
            Iterable<V> iterable,
            Function<? super V, ? extends K> function,
            R concurrentMultimap); static MutableMultimap<K, V> groupBy(
            Iterable<V> iterable,
            Function<? super V, ? extends K> function,
            R concurrentMultimap,
            int batchSize); static MutableMultimap<K, V> groupBy(
            Iterable<V> iterable,
            Function<? super V, ? extends K> function,
            int batchSize); static MutableMultimap<K, V> groupBy(
            Iterable<V> iterable,
            Function<? super V, ? extends K> function,
            int batchSize,
            ForkJoinPool executor); static MutableMultimap<K, V> groupBy(
            Iterable<V> iterable,
            Function<? super V, ? extends K> function,
            R concurrentMultimap,
            int batchSize,
            ForkJoinPool executor); static final int DEFAULT_MIN_FORK_SIZE; }
@Test public void groupByWithInterval() { LazyIterable<Integer> iterable = Interval.oneTo(1000).concatenate(Interval.oneTo(1000)).concatenate(Interval.oneTo(1000)); Multimap<String, Integer> expected = iterable.toBag().groupBy(Functions.getToString()); Multimap<String, Integer> expectedAsSet = iterable.toSet().groupBy(Functions.getToString()); Multimap<String, Integer> result1 = FJIterate.groupBy(iterable.toList(), Functions.getToString(), 100); Multimap<String, Integer> result2 = FJIterate.groupBy(iterable.toList(), Functions.getToString()); Multimap<String, Integer> result3 = FJIterate.groupBy(iterable.toSet(), Functions.getToString(), SynchronizedPutUnifiedSetMultimap.<String, Integer>newMultimap(), 100); Multimap<String, Integer> result4 = FJIterate.groupBy(iterable.toSet(), Functions.getToString(), SynchronizedPutUnifiedSetMultimap.<String, Integer>newMultimap()); Multimap<String, Integer> result5 = FJIterate.groupBy(iterable.toSortedSet(), Functions.getToString(), SynchronizedPutUnifiedSetMultimap.<String, Integer>newMultimap(), 100); Multimap<String, Integer> result6 = FJIterate.groupBy(iterable.toSortedSet(), Functions.getToString(), SynchronizedPutUnifiedSetMultimap.<String, Integer>newMultimap()); Multimap<String, Integer> result7 = FJIterate.groupBy(iterable.toBag(), Functions.getToString(), SynchronizedPutHashBagMultimap.<String, Integer>newMultimap(), 100); Multimap<String, Integer> result8 = FJIterate.groupBy(iterable.toBag(), Functions.getToString(), SynchronizedPutHashBagMultimap.<String, Integer>newMultimap()); Multimap<String, Integer> result9 = FJIterate.groupBy(iterable.toList().toImmutable(), Functions.getToString()); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result1)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result2)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result9)); Assert.assertEquals(expectedAsSet, result3); Assert.assertEquals(expectedAsSet, result4); Assert.assertEquals(expectedAsSet, result5); Assert.assertEquals(expectedAsSet, result6); Assert.assertEquals(expected, result7); Assert.assertEquals(expected, result8); }
@Test public void groupBy() { FastList<String> source = FastList.newListWith("Ted", "Sally", "Mary", "Bob", "Sara"); Multimap<Character, String> result1 = FJIterate.groupBy(source, StringFunctions.firstLetter(), 1); Multimap<Character, String> result2 = FJIterate.groupBy(Collections.synchronizedList(source), StringFunctions.firstLetter(), 1); Multimap<Character, String> result3 = FJIterate.groupBy(Collections.synchronizedCollection(source), StringFunctions.firstLetter(), 1); Multimap<Character, String> result4 = FJIterate.groupBy(LazyIterate.adapt(source), StringFunctions.firstLetter(), 1); Multimap<Character, String> result5 = FJIterate.groupBy(new ArrayList<>(source), StringFunctions.firstLetter(), 1); Multimap<Character, String> result6 = FJIterate.groupBy(source.toSet(), StringFunctions.firstLetter(), 1); Multimap<Character, String> result7 = FJIterate.groupBy(source.toMap(Functions.getStringPassThru(), Functions.getStringPassThru()), StringFunctions.firstLetter(), 1); Multimap<Character, String> result8 = FJIterate.groupBy(source.toBag(), StringFunctions.firstLetter(), 1); Multimap<Character, String> result9 = FJIterate.groupBy(source.toImmutable(), StringFunctions.firstLetter(), 1); MutableMultimap<Character, String> expected = HashBagMultimap.newMultimap(); expected.put('T', "Ted"); expected.put('S', "Sally"); expected.put('M', "Mary"); expected.put('B', "Bob"); expected.put('S', "Sara"); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result1)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result2)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result3)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result4)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result5)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result6)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result7)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result8)); Assert.assertEquals(expected, HashBagMultimap.newMultimap(result9)); Verify.assertThrows(IllegalArgumentException.class, new Runnable() { public void run() { FJIterate.groupBy(null, null, 1); } }); }