Package org.eclipse.collections.api.collection

Interface MutableCollection<T>

All Superinterfaces:
Collection<T>, InternalIterable<T>, Iterable<T>, RichIterable<T>
All Known Subinterfaces:
FixedSizeCollection<T>, FixedSizeList<T>, FixedSizeSet<T>, MultiReaderBag<T>, MultiReaderList<T>, MultiReaderSet<T>, MutableBag<T>, MutableBagIterable<T>, MutableList<T>, MutableSet<T>, MutableSetIterable<T>, MutableSortedBag<T>, MutableSortedSet<T>
All Known Implementing Classes:
AbstractArrayAdapter, AbstractCollectionAdapter, AbstractHashBag, AbstractListAdapter, AbstractMemoryEfficientMutableList, AbstractMultiReaderMutableCollection, AbstractMutableBag, AbstractMutableBagIterable, AbstractMutableCollection, AbstractMutableList, AbstractMutableSet, AbstractMutableSortedBag, AbstractSynchronizedMutableCollection, AbstractUnifiedSet, AbstractUnmodifiableMutableCollection, ArrayAdapter, ArrayListAdapter, CollectionAdapter, CompositeFastList, FastList, HashBag, HashBagWithHashingStrategy, ListAdapter, MultiReaderFastList, MultiReaderHashBag, MultiReaderUnifiedSet, RandomAccessListAdapter, SetAdapter, SortedSetAdapter, SynchronizedBag, SynchronizedMutableCollection, SynchronizedMutableList, SynchronizedMutableSet, SynchronizedSortedBag, SynchronizedSortedSet, TreeBag, TreeSortedSet, UnifiedSet, UnifiedSetWithHashingStrategy, UnmodifiableBag, UnmodifiableMutableCollection, UnmodifiableMutableList, UnmodifiableMutableSet, UnmodifiableSortedBag, UnmodifiableSortedSet
public interface MutableCollection<T> extends Collection<T>, RichIterable<T>
MutableCollection is an interface which extends the base java.util.Collection interface and adds several internal iterator methods, from the Smalltalk Collection protocol. These include variations of forEach, select, reject, detect, collect, injectInto, anySatisfy, allSatisfy. These include count, remove, partition, collectIf. The API also includes converter methods to convert a MutableCollection to a List (toList), to a sorted List (toSortedList), to a Set (toSet), and to a Map (toMap).

There are several extensions to MutableCollection, including MutableList, MutableSet, and MutableBag.

  • Method Details

    • with

      MutableCollection<T> with(T element)
      This method allows mutable and fixed size collections the ability to add elements to their existing elements. In order to support fixed size a new instance of a collection would have to be returned taking the elements of the original collection and appending the new element to form the new collection. In the case of mutable collections, the original collection is modified, and is returned. In order to use this method properly with mutable and fixed size collections the following approach must be taken: 
       MutableCollection<String> list = list.with("1");
 list = list.with("2");
 return list;
      In the case of FixedSizeCollection a new instance of MutableCollection will be returned by with, and any variables that previously referenced the original collection will need to be redirected to reference the new instance. For other MutableCollection types you will replace the reference to collection with the same collection, since the instance will return "this" after calling add on itself.
      See Also:

    • without

      MutableCollection<T> without(T element)
      This method allows mutable and fixed size collections the ability to remove elements from their existing elements. In order to support fixed size a new instance of a collection would have to be returned containing the elements that would be left from the original collection after calling remove. In the case of mutable collections, the original collection is modified, and is returned. In order to use this method properly with mutable and fixed size collections the following approach must be taken: 
       MutableCollection<String> list = list.without("1");
 list = list.without("2");
 return list;
      In the case of FixedSizeCollection a new instance of MutableCollection will be returned by without, and any variables that previously referenced the original collection will need to be redirected to reference the new instance. For other MutableCollection types you will replace the reference to collection with the same collection, since the instance will return "this" after calling remove on itself.
      See Also:

    • withAll

      MutableCollection<T> withAll(Iterable<? extends T> elements)
      This method allows mutable and fixed size collections the ability to add multiple elements to their existing elements. In order to support fixed size a new instance of a collection would have to be returned taking the elements of the original collection and appending the new elements to form the new collection. In the case of mutable collections, the original collection is modified, and is returned. In order to use this method properly with mutable and fixed size collections the following approach must be taken: 
       MutableCollection<String> list = list.withAll(FastList.newListWith("1", "2"));
      In the case of FixedSizeCollection a new instance of MutableCollection will be returned by withAll, and any variables that previously referenced the original collection will need to be redirected to reference the new instance. For other MutableCollection types you will replace the reference to collection with the same collection, since the instance will return "this" after calling addAll on itself.
      See Also:

    • withoutAll

      MutableCollection<T> withoutAll(Iterable<? extends T> elements)
      This method allows mutable and fixed size collections the ability to remove multiple elements from their existing elements. In order to support fixed size a new instance of a collection would have to be returned containing the elements that would be left from the original collection after calling removeAll. In the case of mutable collections, the original collection is modified, and is returned. In order to use this method properly with mutable and fixed size collections the following approach must be taken: 
       MutableCollection<String> list = list.withoutAll(FastList.newListWith("1", "2"));
      In the case of FixedSizeCollection a new instance of MutableCollection will be returned by withoutAll, and any variables that previously referenced the original collection will need to be redirected to reference the new instance. For other MutableCollection types you will replace the reference to collection with the same collection, since the instance will return "this" after calling removeAll on itself.
      See Also:

    • newEmpty

      MutableCollection<T> newEmpty()
      Creates a new empty mutable version of the same collection type. For example, if this instance is a FastList, this method will return a new empty FastList. If the class of this instance is immutable or fixed size (i.e. SingletonList) then a mutable alternative to the class will be provided.

    • tap

      MutableCollection<T> tap(Procedure<? super T> procedure)
      Description copied from interface: RichIterable
      Executes the Procedure for each element in the iterable and returns this.

      Example using a Java 8 lambda expression: 

       RichIterable<Person> tapped =
     people.tap(person -> LOGGER.info(person.getName()));

      Example using an anonymous inner class: 

       RichIterable<Person> tapped =
     people.tap(new Procedure<Person>()
     {
         public void value(Person person)
         {
             LOGGER.info(person.getName());
         }
     });
      Specified by:
      tap in interface RichIterable<T>
      See Also:

    • select

      MutableCollection<T> select(Predicate<? super T> predicate)
      Returns a MutableCollection with all elements that evaluate to true for the specified predicate. 
       MutableCollection<Integer> livesInLondon =
     people.select(person -> person.getAddress().getCity().equals("London"));
      Specified by:
      select in interface RichIterable<T>

    • selectWith

      <P> MutableCollection<T> selectWith(Predicate2<? super T,? super P> predicate, P parameter)
      Returns a MutableCollection with all elements that evaluate to true for the specified predicate2 and parameter. 
       MutableCollection<Integer> fives =
     integers.selectWith(Predicates2.equal(), Integer.valueOf(5));
      Specified by:
      selectWith in interface RichIterable<T>
      Parameters:
      predicate - a Predicate2 to use as the select criteria
      parameter - a parameter to pass in for evaluation of the second argument P in predicate
      See Also:

    • reject

      MutableCollection<T> reject(Predicate<? super T> predicate)
      Returns a MutableCollection with all elements that evaluate to false for the specified predicate. 
       MutableCollection<Person> notSmiths =
     people.reject(person -> person.person.getLastName().equals("Smith"));
      Using the Predicates factory: 
       MutableCollection<Person> notSmiths = people.reject(Predicates.attributeEqual("lastName", "Smith"));
      Specified by:
      reject in interface RichIterable<T>
      Parameters:
      predicate - a Predicate to use as the reject criteria
      Returns:
      a RichIterable that contains elements that cause Predicate.accept(Object) method to evaluate to false

    • rejectWith

      <P> MutableCollection<T> rejectWith(Predicate2<? super T,? super P> predicate, P parameter)
      Returns a MutableCollection with all elements that evaluate to false for the specified predicate2 and parameter. 
      e.g.
 MutableCollection<Integer> selected =
     integers.rejectWith(Predicates2.equal(), Integer.valueOf(5));
      Specified by:
      rejectWith in interface RichIterable<T>
      Parameters:
      predicate - a Predicate2 to use as the select criteria
      parameter - a parameter to pass in for evaluation of the second argument P in predicate
      See Also:

    • selectAndRejectWith

      @Deprecated <P> Twin<MutableList<T>> selectAndRejectWith(Predicate2<? super T,? super P> predicate, P parameter)
      Deprecated.
      since 6.0 use RichIterable.partitionWith(Predicate2, Object) instead.
      Filters a collection into two separate collections based on a predicate returned via a Pair. 
      e.g.
 return lastNames.selectAndRejectWith(Predicates2.lessThan(), "Mason");

    • partition

      PartitionMutableCollection<T> partition(Predicate<? super T> predicate)
      Filters a collection into a PartitionedIterable based on the evaluation of the predicate.

      Example using a Java 8 lambda expression: 

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
     people.partition(person -> person.getAddress().getState().getName().equals("New York"));

      Example using an anonymous inner class: 

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
     people.partition(new Predicate<Person>()
     {
         public boolean accept(Person person)
         {
             return person.getAddress().getState().getName().equals("New York");
         }
     });
      Co-variant example for MutableCollection: 
       PartitionMutableCollection<Person> newYorkersAndNonNewYorkers =
     people.partition(person -> person.getAddress().getState().getName().equals("New York"));
      Specified by:
      partition in interface RichIterable<T>

    • partitionWith

      <P> PartitionMutableCollection<T> partitionWith(Predicate2<? super T,? super P> predicate, P parameter)
      Filters a collection into a PartitionIterable based on the evaluation of the predicate.

      Example using a Java 8 lambda expression: 

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
     people.partitionWith((Person person, String state) -> person.getAddress().getState().getName().equals(state), "New York");

      Example using an anonymous inner class: 

       PartitionIterable<Person> newYorkersAndNonNewYorkers =
     people.partitionWith(new Predicate2<Person, String>()
     {
         public boolean accept(Person person, String state)
         {
             return person.getAddress().getState().getName().equals(state);
         }
     }, "New York");
      Co-variant example for MutableCollection: 
       PartitionMutableCollection<Person> newYorkersAndNonNewYorkers =
     people.partitionWith((Person person, String state) -> person.getAddress().getState().getName().equals(state), "New York");
      Specified by:
      partitionWith in interface RichIterable<T>

    • selectInstancesOf

      <S> MutableCollection<S> selectInstancesOf(Class<S> clazz)
      Returns all elements of the source collection that are instances of the Class clazz. 
       RichIterable<Integer> integers =
     List.mutable.with(new Integer(0), new Long(0L), new Double(0.0)).selectInstancesOf(Integer.class);
      Co-variant example for MutableCollection: 
       MutableCollection<Integer> integers =
     List.mutable.with(new Integer(0), new Long(0L), new Double(0.0)).selectInstancesOf(Integer.class);
      Specified by:
      selectInstancesOf in interface RichIterable<T>
      Since:
      2.0

    • removeIf

      boolean removeIf(Predicate<? super T> predicate)
      Removes all elements in the collection that evaluate to true for the specified predicate. 
      e.g.
 return lastNames.removeIf(Predicates.isNull());

    • removeIfWith

      <P> boolean removeIfWith(Predicate2<? super T,? super P> predicate, P parameter)
      Removes all elements in the collection that evaluate to true for the specified predicate2 and parameter. 
       return lastNames.removeIfWith(Predicates2.isNull(), null);

    • collect

      <V> MutableCollection<V> collect(Function<? super T,? extends V> function)
      Returns a new MutableCollection with the results of applying the specified function to each element of the source collection. 
       MutableCollection<String> names =
     people.collect(person -> person.getFirstName() + " " + person.getLastName());
      Specified by:
      collect in interface RichIterable<T>

    • collectBoolean

      default MutableBooleanCollection collectBoolean(BooleanFunction<? super T> booleanFunction)
      Returns a new primitive boolean iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       BooleanIterable licenses =
     people.collectBoolean(person -> person.hasDrivingLicense());

      Example using an anonymous inner class: 

       BooleanIterable licenses =
     people.collectBoolean(new BooleanFunction<Person>()
     {
         public boolean booleanValueOf(Person person)
         {
             return person.hasDrivingLicense();
         }
     });
      Co-variant example for MutableCollection: 
       MutableBooleanCollection licenses =
     people.collectBoolean(person -> person.hasDrivingLicense());
      Specified by:
      collectBoolean in interface RichIterable<T>

    • collectByte

      default MutableByteCollection collectByte(ByteFunction<? super T> byteFunction)
      Returns a new primitive byte iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       ByteIterable bytes =
     people.collectByte(person -> person.getCode());

      Example using an anonymous inner class: 

       ByteIterable bytes =
     people.collectByte(new ByteFunction<Person>()
     {
         public byte byteValueOf(Person person)
         {
             return person.getCode();
         }
     });
      Co-variant example for MutableCollection: 
       MutableByteCollection bytes =
     people.collectByte(person -> person.getCode());
      Specified by:
      collectByte in interface RichIterable<T>

    • collectChar

      default MutableCharCollection collectChar(CharFunction<? super T> charFunction)
      Returns a new primitive char iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       CharIterable chars =
     people.collectChar(person -> person.getMiddleInitial());

      Example using an anonymous inner class: 

       CharIterable chars =
     people.collectChar(new CharFunction<Person>()
     {
         public char charValueOf(Person person)
         {
             return person.getMiddleInitial();
         }
     });
      Co-variant example for MutableCollection: 
       MutableCharCollection chars =
     people.collectChar(person -> person.getMiddleInitial());
      Specified by:
      collectChar in interface RichIterable<T>

    • collectDouble

      default MutableDoubleCollection collectDouble(DoubleFunction<? super T> doubleFunction)
      Returns a new primitive double iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       DoubleIterable doubles =
     people.collectDouble(person -> person.getMilesFromNorthPole());

      Example using an anonymous inner class: 

       DoubleIterable doubles =
     people.collectDouble(new DoubleFunction<Person>()
     {
         public double doubleValueOf(Person person)
         {
             return person.getMilesFromNorthPole();
         }
     });
      Co-variant example for MutableCollection: 
       MutableDoubleCollection doubles =
     people.collectDouble(person -> person.getMilesFromNorthPole());
      Specified by:
      collectDouble in interface RichIterable<T>

    • collectFloat

      default MutableFloatCollection collectFloat(FloatFunction<? super T> floatFunction)
      Returns a new primitive float iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       FloatIterable floats =
     people.collectFloat(person -> person.getHeightInInches());

      Example using an anonymous inner class: 

       FloatIterable floats =
     people.collectFloat(new FloatFunction<Person>()
     {
         public float floatValueOf(Person person)
         {
             return person.getHeightInInches();
         }
     });
      Co-variant example for MutableCollection: 
       MutableFloatCollection floats =
     people.collectFloat(person -> person.getHeightInInches());
      Specified by:
      collectFloat in interface RichIterable<T>

    • collectInt

      default MutableIntCollection collectInt(IntFunction<? super T> intFunction)
      Returns a new primitive int iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       IntIterable ints =
     people.collectInt(person -> person.getAge());

      Example using an anonymous inner class: 

       IntIterable ints =
     people.collectInt(new IntFunction<Person>()
     {
         public int intValueOf(Person person)
         {
             return person.getAge();
         }
     });
      Co-variant example for MutableCollection: 
       MutableIntCollection ints =
     people.collectInt(person -> person.getAge());
      Specified by:
      collectInt in interface RichIterable<T>

    • collectLong

      default MutableLongCollection collectLong(LongFunction<? super T> longFunction)
      Returns a new primitive long iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       LongIterable longs =
     people.collectLong(person -> person.getGuid());

      Example using an anonymous inner class: 

       LongIterable longs =
     people.collectLong(new LongFunction<Person>()
     {
         public long longValueOf(Person person)
         {
             return person.getGuid();
         }
     });
      Co-variant example for MutableCollection: 
       MutableLongCollection longs =
     people.collectLong(person -> person.getGuid());
      Specified by:
      collectLong in interface RichIterable<T>

    • collectShort

      default MutableShortCollection collectShort(ShortFunction<? super T> shortFunction)
      Returns a new primitive short iterable with the results of applying the specified function on each element of the source collection. This method is also commonly called transform or map.

      Example using a Java 8 lambda expression: 

       ShortIterable shorts =
     people.collectShort(person -> person.getNumberOfJunkMailItemsReceivedPerMonth());

      Example using an anonymous inner class: 

       ShortIterable shorts =
     people.collectShort(new ShortFunction<Person>()
     {
         public short shortValueOf(Person person)
         {
             return person.getNumberOfJunkMailItemsReceivedPerMonth();
         }
     });
      Co-variant example for MutableCollection: 
       MutableShortCollection shorts =
     people.collectShort(person -> person.getNumberOfJunkMailItemsReceivedPerMonth());
      Specified by:
      collectShort in interface RichIterable<T>

    • collectWith

      <P, V> MutableCollection<V> collectWith(Function2<? super T,? super P,? extends V> function, P parameter)
      Same as RichIterable.collect(Function) with a Function2 and specified parameter which is passed to the block.

      Example using a Java 8 lambda expression: 

       RichIterable<Integer> integers =
     Lists.mutable.with(1, 2, 3).collectWith((each, parameter) -> each + parameter, Integer.valueOf(1));

      Example using an anonymous inner class: 

       Function2<Integer, Integer, Integer> addParameterFunction =
     new Function2<Integer, Integer, Integer>()
     {
         public Integer value(Integer each, Integer parameter)
         {
             return each + parameter;
         }
     };
 RichIterable<Integer> integers =
     Lists.mutable.with(1, 2, 3).collectWith(addParameterFunction, Integer.valueOf(1));
      Co-variant example for MutableCollection: 
       MutableCollection<Integer> integers =
     Lists.mutable.with(1, 2, 3).collectWith((each, parameter) -> each + parameter, Integer.valueOf(1));
      Specified by:
      collectWith in interface RichIterable<T>
      Parameters:
      function - A Function2 to use as the collect transformation function
      parameter - A parameter to pass in for evaluation of the second argument P in function
      Returns:
      A new RichIterable that contains the transformed elements returned by Function2.value(Object, Object)
      See Also:

    • collectIf

      <V> MutableCollection<V> collectIf(Predicate<? super T> predicate, Function<? super T,? extends V> function)
      Returns a new MutableCollection with the results of applying the specified function to each element of the source collection, but only for elements that evaluate to true for the specified predicate. 
       MutableCollection<String> collected =
     Lists.mutable.of().with(1, 2, 3).collectIf(Predicates.notNull(), Functions.getToString())
      Specified by:
      collectIf in interface RichIterable<T>

    • flatCollect

      <V> MutableCollection<V> flatCollect(Function<? super T,? extends Iterable<V>> function)
      flatCollect is a special case of RichIterable.collect(Function). With collect, when the Function returns a collection, the result is a collection of collections. flatCollect outputs a single "flattened" collection instead. This method is commonly called flatMap.

      Consider the following example where we have a Person class, and each Person has a list of Address objects. Take the following Function: 

       Function<Person, List<Address>> addressFunction = Person::getAddresses;
 RichIterable<Person> people = ...;
      Using collect returns a collection of collections of addresses. 
       RichIterable<List<Address>> addresses = people.collect(addressFunction);
      Using flatCollect returns a single flattened list of addresses. 
       RichIterable<Address> addresses = people.flatCollect(addressFunction);
      Co-variant example for MutableCollection: 
       Function<Person, List<Address>> addressFunction = Person::getAddresses;
 MutableCollection<Person> people = ...;
 MutableCollection<List<Address>> addresses = people.collect(addressFunction);
 MutableCollection<Address> addresses = people.flatCollect(addressFunction);
      Specified by:
      flatCollect in interface RichIterable<T>
      Parameters:
      function - The Function to apply
      Returns:
      a new flattened collection produced by applying the given function
      Since:
      1.0

    • flatCollectWith

      default <P, V> MutableCollection<V> flatCollectWith(Function2<? super T,? super P,? extends Iterable<V>> function, P parameter)
      Specified by:
      flatCollectWith in interface RichIterable<T>
      Since:
      9.2

    • injectIntoWith

      <IV, P> IV injectIntoWith(IV injectValue, Function3<? super IV,? super T,? super P,? extends IV> function, P parameter)
      Returns the final result of evaluating function using each element of the iterable, the previous evaluation result and the parameters. The injected value is used for the first parameter of the first evaluation, and the current item in the iterable is used as the second parameter. The parameter value is always used as the third parameter to the function call.
      See Also:

    • asUnmodifiable

      MutableCollection<T> asUnmodifiable()
      Returns an unmodifiable view of this collection. This is the equivalent of using Collections.unmodifiableCollection(this) with a return type that supports the full iteration protocols available on MutableCollection. Methods which would mutate the underlying collection will throw UnsupportedOperationExceptions.
      Returns:
      an unmodifiable view of this collection.
      Since:
      1.0
      See Also:

    • asSynchronized

      MutableCollection<T> asSynchronized()
      Returns a synchronized wrapper backed by this collection. This is the equivalent of using Collections.synchronizedCollection(this) only with a return type that supports the full iteration protocols available on MutableCollection. The preferred way of iterating over a synchronized collection is to use the internal iteration methods which are properly synchronized internally. 
        MutableCollection synchedCollection = collection.asSynchronized();
     ...
  synchedCollection.forEach(each -> ... );
  synchedCollection.select(each -> ... );
  synchedCollection.collect(each -> ... );
      If you want to iterate using an imperative style, you must protect external iterators using a synchronized block. This includes explicit iterators as well as JDK 5 style for loops.

      Returns:
      a synchronized view of this collection.
      Since:
      1.0
      See Also:

    • toImmutable

      ImmutableCollection<T> toImmutable()
      Converts this MutableCollection to an ImmutableCollection.
      Since:
      1.0

    • sumByInt

      <V> MutableObjectLongMap<V> sumByInt(Function<? super T,? extends V> groupBy, IntFunction<? super T> function)
      Description copied from interface: RichIterable
      Groups and sums the values using the two specified functions.
      Specified by:
      sumByInt in interface RichIterable<T>

    • sumByFloat

      <V> MutableObjectDoubleMap<V> sumByFloat(Function<? super T,? extends V> groupBy, FloatFunction<? super T> function)
      Description copied from interface: RichIterable
      Groups and sums the values using the two specified functions.
      Specified by:
      sumByFloat in interface RichIterable<T>

    • sumByLong

      <V> MutableObjectLongMap<V> sumByLong(Function<? super T,? extends V> groupBy, LongFunction<? super T> function)
      Description copied from interface: RichIterable
      Groups and sums the values using the two specified functions.
      Specified by:
      sumByLong in interface RichIterable<T>

    • sumByDouble

      <V> MutableObjectDoubleMap<V> sumByDouble(Function<? super T,? extends V> groupBy, DoubleFunction<? super T> function)
      Description copied from interface: RichIterable
      Groups and sums the values using the two specified functions.
      Specified by:
      sumByDouble in interface RichIterable<T>

    • countBy

      default <V> MutableBag<V> countBy(Function<? super T,? extends V> function)
      Description copied from interface: RichIterable
      This method will count the number of occurrences of each value calculated by applying the function to each element of the collection.
      Specified by:
      countBy in interface RichIterable<T>
      Since:
      9.0

    • countByWith

      default <V, P> MutableBag<V> countByWith(Function2<? super T,? super P,? extends V> function, P parameter)
      Description copied from interface: RichIterable
      This method will count the number of occurrences of each value calculated by applying the function to each element of the collection with the specified parameter as the second argument.
      Specified by:
      countByWith in interface RichIterable<T>
      Since:
      9.0

    • countByEach

      default <V> MutableBag<V> countByEach(Function<? super T,? extends Iterable<V>> function)
      Description copied from interface: RichIterable
      This method will count the number of occurrences of each value calculated by applying the function to each element of the collection.
      Specified by:
      countByEach in interface RichIterable<T>
      Since:
      10.0.0

    • groupBy

      <V> MutableMultimap<V,T> groupBy(Function<? super T,? extends V> function)
      For each element of the iterable, the function is evaluated and the results of these evaluations are collected into a new multimap, where the transformed value is the key and the original values are added to the same (or similar) species of collection as the source iterable.

      Example using a Java 8 method reference: 

       Multimap<String, Person> peopleByLastName =
     people.groupBy(Person::getLastName);

      Example using an anonymous inner class: 

       Multimap<String, Person> peopleByLastName =
     people.groupBy(new Function<Person, String>()
     {
         public String valueOf(Person person)
         {
             return person.getLastName();
         }
     });
      Co-variant example for MutableCollection: 
       MutableMultimap<String, Person> peopleByLastName =
     people.groupBy(Person::getLastName);
      Specified by:
      groupBy in interface RichIterable<T>

    • groupByEach

      <V> MutableMultimap<V,T> groupByEach(Function<? super T,? extends Iterable<V>> function)
      Description copied from interface: RichIterable
      Similar to RichIterable.groupBy(Function), except the result of evaluating function will return a collection of keys for each value.
      Specified by:
      groupByEach in interface RichIterable<T>

    • groupByUniqueKey

      default <V> MutableMap<V,T> groupByUniqueKey(Function<? super T,? extends V> function)
      Description copied from interface: RichIterable
      For each element of the iterable, the function is evaluated, and the results of these evaluations are collected into a new map, where the transformed value is the key. The generated keys must each be unique, or else an exception is thrown.
      Specified by:
      groupByUniqueKey in interface RichIterable<T>
      See Also:

    • zip

      @Deprecated <S> MutableCollection<Pair<T,S>> zip(Iterable<S> that)
      Deprecated.
      in 6.0. Use OrderedIterable.zip(Iterable) instead.
      Description copied from interface: RichIterable
      Returns a RichIterable formed from this RichIterable and another RichIterable by combining corresponding elements in pairs. If one of the two RichIterables is longer than the other, its remaining elements are ignored.
      Specified by:
      zip in interface RichIterable<T>
      Type Parameters:
      S - the type of the second half of the returned pairs
      Parameters:
      that - The RichIterable providing the second half of each result pair
      Returns:
      A new RichIterable containing pairs consisting of corresponding elements of this RichIterable and that. The length of the returned RichIterable is the minimum of the lengths of this RichIterable and that.

    • zipWithIndex

      @Deprecated MutableCollection<Pair<T,Integer>> zipWithIndex()
      Deprecated.
      in 6.0. Use OrderedIterable.zipWithIndex() instead.
      Description copied from interface: RichIterable
      Zips this RichIterable with its indices.
      Specified by:
      zipWithIndex in interface RichIterable<T>
      Returns:
      A new RichIterable containing pairs consisting of all elements of this RichIterable paired with their index. Indices start at 0.
      See Also:

    • addAllIterable

      boolean addAllIterable(Iterable<? extends T> iterable)
      Since:
      1.0
      See Also:

    • removeAllIterable

      boolean removeAllIterable(Iterable<?> iterable)
      Since:
      1.0
      See Also:

    • retainAllIterable

      boolean retainAllIterable(Iterable<?> iterable)
      Since:
      1.0
      See Also:

    • aggregateInPlaceBy

      default <K, V> MutableMap<K,V> aggregateInPlaceBy(Function<? super T,? extends K> groupBy, Function0<? extends V> zeroValueFactory, Procedure2<? super V,? super T> mutatingAggregator)
      Description copied from interface: RichIterable
      Applies an aggregate procedure over the iterable grouping results into a Map based on the specific groupBy function. Aggregate results are required to be mutable as they will be changed in place by the procedure. A second function specifies the initial "zero" aggregate value to work with (i.e. new AtomicInteger(0)).
      Specified by:
      aggregateInPlaceBy in interface RichIterable<T>

    • aggregateBy

      default <K, V> MutableMap<K,V> aggregateBy(Function<? super T,? extends K> groupBy, Function0<? extends V> zeroValueFactory, Function2<? super V,? super T,? extends V> nonMutatingAggregator)
      Description copied from interface: RichIterable
      Applies an aggregate function over the iterable grouping results into a map based on the specific groupBy function. Aggregate results are allowed to be immutable as they will be replaced in place in the map. A second function specifies the initial "zero" aggregate value to work with (i.e. Integer.valueOf(0)).
      Specified by:
      aggregateBy in interface RichIterable<T>