| Package | Description | 
|---|---|
| java.util | Contains the collections framework, legacy collection classes, event model,
date and time facilities, internationalization, and miscellaneous utility
classes (a string tokenizer, a random-number generator, and a bit array). | 
| java.util.concurrent | Utility classes commonly useful in concurrent programming. | 
| java.util.concurrent.atomic | A small toolkit of classes that support lock-free thread-safe
 programming on single variables. | 
| java.util.stream | Classes to support functional-style operations on streams of elements, such
 as map-reduce transformations on collections. | 
| Modifier and Type | Method and Description | 
|---|---|
| static void | Arrays. parallelPrefix(double[] array,
              DoubleBinaryOperator op)Cumulates, in parallel, each element of the given array in place,
 using the supplied function. | 
| static void | Arrays. parallelPrefix(double[] array,
              int fromIndex,
              int toIndex,
              DoubleBinaryOperator op)Performs  Arrays.parallelPrefix(double[], DoubleBinaryOperator)for the given subrange of the array. | 
| Modifier and Type | Method and Description | 
|---|---|
| double | ConcurrentHashMap. reduceEntriesToDouble(long parallelismThreshold,
                     ToDoubleFunction<Map.Entry<K,V>> transformer,
                     double basis,
                     DoubleBinaryOperator reducer)Returns the result of accumulating the given transformation
 of all entries using the given reducer to combine values,
 and the given basis as an identity value. | 
| double | ConcurrentHashMap. reduceKeysToDouble(long parallelismThreshold,
                  ToDoubleFunction<? super K> transformer,
                  double basis,
                  DoubleBinaryOperator reducer)Returns the result of accumulating the given transformation
 of all keys using the given reducer to combine values, and
 the given basis as an identity value. | 
| double | ConcurrentHashMap. reduceToDouble(long parallelismThreshold,
              ToDoubleBiFunction<? super K,? super V> transformer,
              double basis,
              DoubleBinaryOperator reducer)Returns the result of accumulating the given transformation
 of all (key, value) pairs using the given reducer to
 combine values, and the given basis as an identity value. | 
| double | ConcurrentHashMap. reduceValuesToDouble(long parallelismThreshold,
                    ToDoubleFunction<? super V> transformer,
                    double basis,
                    DoubleBinaryOperator reducer)Returns the result of accumulating the given transformation
 of all values using the given reducer to combine values,
 and the given basis as an identity value. | 
| Constructor and Description | 
|---|
| DoubleAccumulator(DoubleBinaryOperator accumulatorFunction,
                 double identity)Creates a new instance using the given accumulator function
 and identity element. | 
| Modifier and Type | Method and Description | 
|---|---|
| OptionalDouble | DoubleStream. reduce(DoubleBinaryOperator op)Performs a reduction on the
 elements of this stream, using an
 associative accumulation
 function, and returns an  OptionalDoubledescribing the reduced
 value, if any. | 
| double | DoubleStream. reduce(double identity,
      DoubleBinaryOperator op)Performs a reduction on the
 elements of this stream, using the provided identity value and an
 associative
 accumulation function, and returns the reduced value. | 
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