DoubleStreams (net.sourceforge.streamsupport:streamsupport 1.6.2 API)

java.lang.Object
- java8.util.stream.DoubleStreams

```
public final class DoubleStreams
extends Object
```
A place for static default implementations of the new Java 8/9 static interface methods and default interface methods (takeWhile(), dropWhile()) in the DoubleStream interface.

Method Summary

All Methods Static Methods Concrete Methods
Modifier and Type	Method and Description
`static DoubleStream.Builder`	`builder()` Returns a builder for a `DoubleStream`.
`static DoubleStream`	`concat(DoubleStream a, DoubleStream b)` Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream.
`static DoubleStream`	`dropWhile(DoubleStream stream, DoublePredicate predicate)` Returns a stream consisting of the remaining elements of the passed stream after discarding elements that match the given predicate up to, but not discarding, the first element encountered that does not match the predicate.
`static DoubleStream`	`empty()` Returns an empty sequential `DoubleStream`.
`static DoubleStream`	`generate(DoubleSupplier s)` Returns an infinite sequential unordered stream where each element is generated by the provided `DoubleSupplier`.
`static DoubleStream`	`iterate(double seed, DoublePredicate hasNext, DoubleUnaryOperator next)` Returns a sequential ordered `DoubleStream` produced by iterative application of the given `next` function to an initial element, conditioned on satisfying the given `hasNext` predicate.
`static DoubleStream`	`iterate(double seed, DoubleUnaryOperator f)` Returns an infinite sequential ordered `DoubleStream` produced by iterative application of a function `f` to an initial element `seed`, producing a `Stream` consisting of `seed`, `f(seed)`, `f(f(seed))`, etc.
`static DoubleStream`	`of(double... values)` Returns a sequential ordered stream whose elements are the specified values.
`static DoubleStream`	`of(double t)` Returns a sequential `DoubleStream` containing a single element.
`static DoubleStream`	`takeWhile(DoubleStream stream, DoublePredicate predicate)` Returns a stream consisting of elements of the passed stream that match the given predicate up to, but discarding, the first element encountered that does not match the predicate.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Method Detail
  - takeWhile
```
public static DoubleStream takeWhile(DoubleStream stream,
                                     DoublePredicate predicate)
```
    Returns a stream consisting of elements of the passed stream that match the given predicate up to, but discarding, the first element encountered that does not match the predicate. All subsequently encountered elements are discarded.
    This is a short-circuiting stateful intermediate operation.
    
    Parameters:
    
    stream - the stream to wrap for the takeWhile() operation
    
    predicate - a non-interfering, predicate to apply to each element to determine if it should be included, or it and all subsequently encountered elements be discarded.
    
    Returns:
    
    the new stream
    
    Since:
    
    9
  - dropWhile
```
public static DoubleStream dropWhile(DoubleStream stream,
                                     DoublePredicate predicate)
```
    Returns a stream consisting of the remaining elements of the passed stream after discarding elements that match the given predicate up to, but not discarding, the first element encountered that does not match the predicate. All subsequently encountered elements are not discarded.
    This is a stateful intermediate operation.
    
    Parameters:
    
    stream - the stream to wrap for the dropWhile() operation
    
    predicate - a non-interfering, predicate to apply to each element to determine if it should be discarded, or it and all subsequently encountered elements be included.
    
    Returns:
    
    the new stream
    
    Since:
    
    9
  - builder
```
public static DoubleStream.Builder builder()
```
    Returns a builder for a DoubleStream.
    
    Returns:
    
    a stream builder
  - empty
```
public static DoubleStream empty()
```
    Returns an empty sequential DoubleStream.
    
    Returns:
    
    an empty sequential stream
  - of
```
public static DoubleStream of(double t)
```
    Returns a sequential DoubleStream containing a single element.
    
    Parameters:
    
    t - the single element
    
    Returns:
    
    a singleton sequential stream
  - of
```
public static DoubleStream of(double... values)
```
    Returns a sequential ordered stream whose elements are the specified values.
    
    Parameters:
    
    values - the elements of the new stream
    
    Returns:
    
    the new stream
  - iterate
```
public static DoubleStream iterate(double seed,
                                   DoubleUnaryOperator f)
```
    Returns an infinite sequential ordered DoubleStream produced by iterative application of a function f to an initial element seed, producing a Stream consisting of seed, f(seed), f(f(seed)), etc.
    The first element (position 0) in the DoubleStream will be the provided seed. For n > 0, the element at position n, will be the result of applying the function f to the element at position n - 1.
    The action of applying f for one element happens-before the action of applying f for subsequent elements. For any given element the action may be performed in whatever thread the library chooses.
    
    Parameters:
    
    seed - the initial element
    
    f - a function to be applied to the previous element to produce a new element
    
    Returns:
    
    a new sequential DoubleStream
  - iterate
```
public static DoubleStream iterate(double seed,
                                   DoublePredicate hasNext,
                                   DoubleUnaryOperator next)
```
    Returns a sequential ordered DoubleStream produced by iterative application of the given next function to an initial element, conditioned on satisfying the given hasNext predicate. The stream terminates as soon as the hasNext predicate returns false.
    DoubleStreams.iterate should produce the same sequence of elements as produced by the corresponding for-loop:
```
     for (double index=seed; hasNext.test(index); index = next.applyAsDouble(index)) {
         ... 
     }
 
```
    The resulting sequence may be empty if the hasNext predicate does not hold on the seed value. Otherwise the first element will be the supplied seed value, the next element (if present) will be the result of applying the next function to the seed value, and so on iteratively until the hasNext predicate indicates that the stream should terminate.
    The action of applying the hasNext predicate to an element happens-before the action of applying the next function to that element. The action of applying the next function for one element happens-before the action of applying the hasNext predicate for subsequent elements. For any given element an action may be performed in whatever thread the library chooses.
    Parameters:
    
    seed - the initial element
    
    hasNext - a predicate to apply to elements to determine when the stream must terminate
    
    next - a function to be applied to the previous element to produce a new element
    
    Returns:
    
    a new sequential DoubleStream
    
    Since:
    
    9
  - generate
```
public static DoubleStream generate(DoubleSupplier s)
```
    Returns an infinite sequential unordered stream where each element is generated by the provided DoubleSupplier. This is suitable for generating constant streams, streams of random elements, etc.
    
    Parameters:
    
    s - the DoubleSupplier for generated elements
    
    Returns:
    
    a new infinite sequential unordered DoubleStream
  - concat
```
public static DoubleStream concat(DoubleStream a,
                                  DoubleStream b)
```
    Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream. The resulting stream is ordered if both of the input streams are ordered, and parallel if either of the input streams is parallel. When the resulting stream is closed, the close handlers for both input streams are invoked.
    This method operates on the two input streams and binds each stream to its source. As a result subsequent modifications to an input stream source may not be reflected in the concatenated stream result.
    Implementation Note:
    Use caution when constructing streams from repeated concatenation. Accessing an element of a deeply concatenated stream can result in deep call chains, or even StackOverflowError.
    Subsequent changes to the sequential/parallel execution mode of the returned stream are not guaranteed to be propagated to the input streams.
    API Note:
    To preserve optimization opportunities this method binds each stream to its source and accepts only two streams as parameters. For example, the exact size of the concatenated stream source can be computed if the exact size of each input stream source is known. To concatenate more streams without binding, or without nested calls to this method, try creating a stream of streams and flat-mapping with the identity function, for example:
```
     DoubleStream concat = RefStreams.of(s1, s2, s3, s4).flatMapToDouble(s -> s);
 
```
    Parameters:
    
    a - the first stream
    
    b - the second stream
    
    Returns:
    
    the concatenation of the two input streams

Class DoubleStreams

Method Summary

Methods inherited from class java.lang.Object

Method Detail

takeWhile

dropWhile

builder

empty

of

of

iterate

iterate

generate

concat