7.0.0 (October 2015)

Acquiring GS Collections

Maven

<dependency>
    <groupId>com.goldmansachs</groupId>
    <artifactId>gs-collections-api</artifactId>
    <version>7.0.0</version>
</dependency>

<dependency>
    <groupId>com.goldmansachs</groupId>
    <artifactId>gs-collections</artifactId>
    <version>7.0.0</version>
</dependency>

<dependency>
    <groupId>com.goldmansachs</groupId>
    <artifactId>gs-collections-testutils</artifactId>
    <version>7.0.0</version>
    <scope>test</scope>
</dependency>

<dependency>
    <groupId>com.goldmansachs</groupId>
    <artifactId>gs-collections-forkjoin</artifactId>
    <version>7.0.0</version>
</dependency>

Ivy

<dependency org="com.goldmansachs" name="gs-collections-api" rev="7.0.0" />
<dependency org="com.goldmansachs" name="gs-collections" rev="7.0.0" />
<dependency org="com.goldmansachs" name="gs-collections-testutils" rev="7.0.0" />
<dependency org="com.goldmansachs" name="gs-collections-forkjoin" rev="7.0.0"/>

Breaking Changes

• MutableCollection.removeIf() now returns boolean.
• Sorted sets, bags, and maps implement ReversibleIterable. Added OrderedMap interface to represent a linked hash map.
• Overrode BiMap.partition() to return PartitionUnsortedSet.
• UnifiedMap and UnifiedSet now throw if constructed with a load factor greater than 1.
• toStringOfItemToCount() in ImmutableEmptyBag now consistent with other Bags.
  Returns "{}" instead of ""

New Functionality

Primitive Collections

<Primitive>List.binarySearch() Fixes #20

ObjectPrimitiveHashMapWithHashingStrategy

Similar to ObjectPrimitiveHashMap but uses a HashingStrategy to hash and compare keys. Analogous to UnifiedMapWithHashingStrategy.

<Primitive>Iterable.each()

Behaves exactly same as <Primitive>Iterable.forEach(). Added to be in sync with RichIterable.each(Procedure) that was introduced in 6.0 to avoid ambiguity conflict with Iterable.forEach(Consumer).

Lazy<Primitive>Iterable.collect<Primitive>()

aggregateInPlaceBy(), aggregateBy(), zip(), zipWithIndex(), partition(), selectInstancesOf(), collectIf(), groupBy(), and groupByEach() on MutablePrimitiveObjectMap

Use the Kahan summation algorithm on sum() and sumBy() methods on primitive collections

Other new Functionality

CharAdapter, CodePointAdapter and CodePointList

• CharAdapter implements CharSequence and ImmutableCharList, and it represents String as a collection of char values.
• CharPointAdapter implements CharSequence and ImmutableIntList. It behaves similarly to CharAdapter but it represents String as the unicode codepoint values that are ints.
• CharPointList is similar to CharPointAdapter but it calculates and caches the unicode code point values as an ImmutableIntList internally.

CharAdapter chars = CharAdapter.adapt("This is an example");
CodePointAdapter codePoints = CodePointAdapter.adapt("Can you read this Kanji \"\uD840\uDC00\"? I cannot.");
CodePointList codePointList = CodePointList.from("BMP stands for Basic Multilingual Pane. \"\uD840\uDC00\" is a unicode character outside BMP.");

System.out.println("Upper case: " + chars.collectChar(Character::toUpperCase));
System.out.println("Unicode character outside Basic Multilingual Pane: " + codePoints.reject(Character::isBmpCodePoint).distinct());
System.out.println("English only: " + codePointList.reject(Character::isIdeographic));

Prints

Upper case: THIS IS AN EXAMPLE
Unicode character outside Basic Multilingual Pane: 𠀀
English only: BMP stands for Basic Multilingual Pane. "" is a unicode character outside BMP.

ImmutableSortedBag

ListIterable.distinct(HashingStrategy)

Returns a new ListIterable containing the distinct elements in this list. Conceptually similar to new UnifiedSetWithHashingStrategy(hashingStrategy, listIterable).toList() but retains the original order.

MutableBagMultimap.putOccurrences(K key, V value, int occurrences)

Adds occurrences of value to the MutableBag at key in the multimap.

MutableList.shuffleThis(): MutableList

Shuffles this list and returns this list. Overload optionally takes a Random.

Predicates.cast() and Functions.cast()

Allows a Java 8 lambda or method reference to be used in a method taking a predicate or a function without requiring a cast. The methods can be used in places where two or more method overloads could apply when used with a lambda or method reference.

Lists.mutable.of(1, 2, null).removeIf(each -> each == null);

This code fails to compile with the following error.

Error: java: reference to removeIf is ambiguous
both method removeIf(java.util.function.Predicate<? super E>) in java.util.Collection and method removeIf(com.gs.collections.api.block.predicate.Predicate<? super T>) in com.gs.collections.api.collection.MutableCollection match

You can work around the problem by using a cast or the method Predicates.cast().

Lists.mutable.of(1, 2, null).removeIf(Predicates.cast(each -> each == null));

Add factory method for creating mutable sets and maps of a given initial capacity.

For example: Sets.mutable.withInitialCapacity(100)

Optimizations and Performance Tests

• Optimize FastList.addAll() and UnifiedSet.addAll() for RandomAccess lists.
• Optimize UnifiedMap's short-circuit methods to not delegate to an iterator.
• Refactor ImmutableSortedBag.newWith() and newWithout() to take O(n) time.
• Add JDK 8 Streams based JMH tests for FastList.
• Add JMH Tests for HashMap<Integer, Integer>

Bug Fixes

• Fix bug in CollectIterable.toArray() where it returns T[] instead of Object[].
• Fix iterator's remove() method in ObjectPrimitiveHashMap so that it doesn't rehash.
• Fix code point iteration in StringIterate and provide CharAdapter and CodePointList as OO alternatives for string iteration.

Documentation and Deprecation

• Add information about required Java versions to README.md. Fixes #18.
• Enhance Javadoc of Iterate.
• Update Javadoc in InternalIterable and RichIterable to include Java 8 lambda examples.
• Deprecate ArrayIterate.sort() and recommend direct calls to Arrays.sort().
• Deprecate overloaded methods in StringIterate and add specialization alternatives that work better with Java 8 lambdas.