StreamCore (gpars 1.2.1)

java.lang.Object
- groovyx.gpars.dataflow.stream.StreamCore<T>

Type Parameters:
T - Type for values to pass through the channels

All Implemented Interfaces:

FList<T>, java.lang.Iterable<T>

Direct Known Subclasses:

DataflowStream, SyncDataflowStream
```
public abstract class StreamCore<T>
extends java.lang.Object
implements FList<T>
```
Represents a common base for publish-subscribe deterministic channels.

Author:

Johannes Link, Vaclav Pech

Field Summary

Fields
Modifier and Type	Field and Description
`protected DataflowVariable<T>`	`first`
`protected java.util.concurrent.atomic.AtomicReference<StreamCore<T>>`	`rest`
`protected java.util.Collection<MessageStream>`	`wheneverBoundListeners` A collection of listeners who need to be informed each time the stream is bound to a value

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`StreamCore(DataflowVariable<T> first)` Creates an empty stream
`protected`	`StreamCore(DataflowVariable<T> first, groovy.lang.Closure toBeApplied)` Creates a stream while applying the supplied initialization closure to it
`protected`	`StreamCore(DataflowVariable<T> first, java.util.Collection<MessageStream> wheneverBoundListeners, java.util.Collection<DataflowChannelListener<T>> updateListeners)`

Method Summary

Methods
Modifier and Type	Method and Description
`(package private) void`	`addUpdateListener(DataflowChannelListener<T> updateListener)`
`private void`	`addUpdateListeners(java.util.Collection<DataflowChannelListener<T>> updateListeners)`
`java.lang.String`	`appendingString()`
`StreamCore<T>`	`apply(groovy.lang.Closure closure)` Calls the supplied closure with the stream as a parameter
`private void`	`bind(T value)`
`protected abstract StreamCore<T>`	`createNewStream()` A factory method to create new instances of the correct class when needed
`void`	`decrementParties()` Decreases the number of parties required to perform the data exchange
`static <T> T`	`eos()`
`boolean`	`equals(java.lang.Object obj)`
`private static <T> T`	`eval(java.lang.Object valueOrDataflowVariable)`
`FList<T>`	`filter(groovy.lang.Closure filterClosure)` Builds a filtered stream using the supplied filter closure
`private void`	`filter(StreamCore<T> rest, groovy.lang.Closure filterClosure, StreamCore<T> result)`
`StreamCore<T>`	`generate(T seed, groovy.lang.Closure generator, groovy.lang.Closure condition)` Populates the stream with generated values
`private void`	`generateNext(T value, StreamCore<T> stream, groovy.lang.Closure generator, groovy.lang.Closure condition)`
`T`	`getFirst()` Retrieved the first element in the stream, blocking until a value is available
`(package private) DataflowVariable<T>`	`getFirstDFV()`
`abstract FList<T>`	`getRest()` Retrieves a DataflowStream representing the rest of this Stream after removing the first element
`int`	`hashCode()`
`private DataflowExpression<T>`	`hookWheneverBoundListeners(DataflowExpression<T> expr)` Hooks the registered when bound handlers to the supplied dataflow expression
`void`	`incrementParties()` Increases the number of parties required to perform the data exchange
`boolean`	`isEmpty()` Indicates, whether the first element in the stream is an eos
`java.util.Iterator<T>`	`iterator()` Builds an iterator to iterate over the stream
`StreamCore<T>`	`leftShift(DataflowReadChannel<T> ref)` Adds a dataflow variable value to the stream, once the value is available
`StreamCore<T>`	`leftShift(T value)` Adds a value to the stream
`FList<java.lang.Object>`	`map(groovy.lang.Closure mapClosure)` Builds a modified stream using the supplied map closure
`private void`	`map(FList<T> rest, groovy.lang.Closure mapClosure, StreamCore<java.lang.Object> result)`
`T`	`reduce(groovy.lang.Closure reduceClosure)` Reduces all elements in the stream using the supplied closure
`T`	`reduce(T seed, groovy.lang.Closure reduceClosure)` Reduces all elements in the stream using the supplied closure
`private T`	`reduce(T current, FList<T> rest, groovy.lang.Closure reduceClosure)`
`void`	`wheneverBound(groovy.lang.Closure closure)`
`void`	`wheneverBound(MessageStream stream)`

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

- Field Detail
  - first
```
protected final DataflowVariable<T> first
```
  - rest
```
protected final java.util.concurrent.atomic.AtomicReference<StreamCore<T>> rest
```
  - wheneverBoundListeners
```
protected final java.util.Collection<MessageStream> wheneverBoundListeners
```
    A collection of listeners who need to be informed each time the stream is bound to a value
- Constructor Detail
  - StreamCore
```
protected StreamCore(DataflowVariable<T> first)
```
    Creates an empty stream
    
    Parameters:
    first - The variable to store as the head of the stream
  - StreamCore
```
protected StreamCore(DataflowVariable<T> first,
          groovy.lang.Closure toBeApplied)
```
    Creates a stream while applying the supplied initialization closure to it
    
    Parameters:
    first - The variable to store as the head of the stream
    toBeApplied - The closure to use for initialization
  - StreamCore
```
protected StreamCore(DataflowVariable<T> first,
          java.util.Collection<MessageStream> wheneverBoundListeners,
          java.util.Collection<DataflowChannelListener<T>> updateListeners)
```
- Method Detail
  - addUpdateListeners
```
private void addUpdateListeners(java.util.Collection<DataflowChannelListener<T>> updateListeners)
```
  - addUpdateListener
```
final void addUpdateListener(DataflowChannelListener<T> updateListener)
```
  - eos
```
public static <T> T eos()
```
  - eval
```
private static <T> T eval(java.lang.Object valueOrDataflowVariable)
```
  - generate
```
public final StreamCore<T> generate(T seed,
                     groovy.lang.Closure generator,
                     groovy.lang.Closure condition)
```
    Populates the stream with generated values
    
    Parameters:
    seed - The initial element to evaluate and add as the first value of the stream
    generator - A closure generating stream elements from the previous values
    condition - A closure indicating whether the generation should continue based on the last generated value
    
    Returns:
    This stream
  - generateNext
```
private void generateNext(T value,
                StreamCore<T> stream,
                groovy.lang.Closure generator,
                groovy.lang.Closure condition)
```
  - apply
```
public final StreamCore<T> apply(groovy.lang.Closure closure)
```
    Calls the supplied closure with the stream as a parameter
    
    Parameters:
    closure - The closure to call
    
    Returns:
    This instance of DataflowStream
  - leftShift
```
public final StreamCore<T> leftShift(DataflowReadChannel<T> ref)
```
    Adds a dataflow variable value to the stream, once the value is available
    
    Parameters:
    ref - The DataflowVariable to check for value
    
    Returns:
    The rest of the stream
  - leftShift
```
public final StreamCore<T> leftShift(T value)
```
    Adds a value to the stream
    
    Parameters:
    value - The value to add
    
    Returns:
    The rest of the stream
  - bind
```
private void bind(T value)
```
  - getFirstDFV
```
final DataflowVariable<T> getFirstDFV()
```
  - getFirst
```
public final T getFirst()
```
    Retrieved the first element in the stream, blocking until a value is available
    
    Specified by:
    
    getFirst in interface FList<T>
    
    Returns:
    The first item in the stream
  - getRest
```
public abstract FList<T> getRest()
```
    Retrieves a DataflowStream representing the rest of this Stream after removing the first element
    
    Specified by:
    
    getRest in interface FList<T>
    
    Returns:
    The remaining stream elements
  - isEmpty
```
public final boolean isEmpty()
```
    Indicates, whether the first element in the stream is an eos
    
    Specified by:
    
    isEmpty in interface FList<T>
  - filter
```
public final FList<T> filter(groovy.lang.Closure filterClosure)
```
    Builds a filtered stream using the supplied filter closure
    
    Specified by:
    
    filter in interface FList<T>
    
    Parameters:
    filterClosure - The closure to decide on inclusion of elements
    
    Returns:
    The first item of the filtered stream
  - filter
```
private void filter(StreamCore<T> rest,
          groovy.lang.Closure filterClosure,
          StreamCore<T> result)
```
  - map
```
public final FList<java.lang.Object> map(groovy.lang.Closure mapClosure)
```
    Builds a modified stream using the supplied map closure
    
    Specified by:
    
    map in interface FList<T>
    
    Parameters:
    mapClosure - The closure to transform elements
    
    Returns:
    The first item of the transformed stream
  - map
```
private void map(FList<T> rest,
       groovy.lang.Closure mapClosure,
       StreamCore<java.lang.Object> result)
```
  - reduce
```
public final T reduce(groovy.lang.Closure reduceClosure)
```
    Reduces all elements in the stream using the supplied closure
    
    Specified by:
    
    reduce in interface FList<T>
    
    Parameters:
    reduceClosure - The closure to reduce elements of the stream gradually into an accumulator. The accumulator is seeded with the first stream element.
    
    Returns:
    The result of reduction of the whole stream
  - reduce
```
public final T reduce(T seed,
       groovy.lang.Closure reduceClosure)
```
    Reduces all elements in the stream using the supplied closure
    
    Specified by:
    
    reduce in interface FList<T>
    
    Parameters:
    reduceClosure - The closure to reduce elements of the stream gradually into an accumulator.
    seed - The value to initialize the accumulator with.
    
    Returns:
    The result of reduction of the whole stream
  - reduce
```
private T reduce(T current,
       FList<T> rest,
       groovy.lang.Closure reduceClosure)
```
  - iterator
```
public final java.util.Iterator<T> iterator()
```
    Builds an iterator to iterate over the stream
    
    Specified by:
    
    iterator in interface java.lang.Iterable<T>
    
    Returns:
    A new FListIterator instance
  - appendingString
```
public java.lang.String appendingString()
```
    Specified by:
    
    appendingString in interface FList<T>
  - equals
```
public boolean equals(java.lang.Object obj)
```
    Overrides:
    
    equals in class java.lang.Object
  - hashCode
```
public int hashCode()
```
    Overrides:
    
    hashCode in class java.lang.Object
  - createNewStream
```
protected abstract StreamCore<T> createNewStream()
```
    A factory method to create new instances of the correct class when needed
    
    Returns:
    An instance of the appropriate sub-class
  - wheneverBound
```
public final void wheneverBound(groovy.lang.Closure closure)
```
  - wheneverBound
```
public final void wheneverBound(MessageStream stream)
```
  - hookWheneverBoundListeners
```
private DataflowExpression<T> hookWheneverBoundListeners(DataflowExpression<T> expr)
```
    Hooks the registered when bound handlers to the supplied dataflow expression
    
    Parameters:
    expr - The expression to hook all the when bound listeners to
    
    Returns:
    The supplied expression handler to allow method chaining
  - incrementParties
```
public void incrementParties()
```
    Increases the number of parties required to perform the data exchange
  - decrementParties
```
public void decrementParties()
```
    Decreases the number of parties required to perform the data exchange

Class StreamCore<T>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

first

rest

wheneverBoundListeners

Constructor Detail

StreamCore

StreamCore

StreamCore

Method Detail

addUpdateListeners

addUpdateListener

eos

eval

generate

generateNext

apply

leftShift

leftShift

bind

getFirstDFV

getFirst

getRest

isEmpty

filter

filter

map

map

reduce

reduce

reduce

iterator

appendingString

equals

hashCode

createNewStream

wheneverBound

wheneverBound

hookWheneverBoundListeners

incrementParties

decrementParties