XCollection (Talon 3.14.19 API)

java.lang.Object
- com.neeve.lang.XCollection<E>

All Implemented Interfaces:

Iterable<E>, Collection<E>

Direct Known Subclasses:

XIndexedList, XLinkedList
```
public abstract class XCollection<E>
extends Object
implements Collection<E>
```
This class represents collections which can quickly be iterated over (forward or backward) and which an be made thread-safe and/or unmodifiable.

XCollections can be iterated over without creating new objects and without using iterators . [code] public boolean search(Object item, XCollection c) { for (Record r = c.head(), end = c.tail(); (r = r.getNext()) != end;) { if (item.equals(c.valueOf(r))) return true; } return false; } [/code]

Alternatively XCollection}s can be iterated over using reusableIterator(), Utilization of this iterators does not introduce garbage because it is created once. This iterator may not be used concurrently by multiple threads as they are single instance by nature.
XCollections are thread-safe when marked shared (can be read, iterated over or modified concurrently). [code] public class Foo { private static final Collection INSTANCES = new XLinkedHashMap().shared(); public Foo() { INSTANCES.add(this); } public static void showInstances() { for (Foo foo : INSTANCES) { // Iterations are thread-safe even if new Foo instances are added. System.out.println(foo); } } }[/code]

This class was based on collections code from http://javolution.org, but modified for use outside of realtime jvms.

Nested Class Summary

Nested Classes
Modifier and Type Class and Description

static interface XCollection.Record
This interface represents the collection records which can directly be iterated over.

Nested Classes
Modifier and Type	Class and Description
`static interface`	`XCollection.Record` This interface represents the collection records which can directly be iterated over.

Method Summary

Methods
Modifier and Type	Method and Description
`boolean`	`add(E value)` Appends the specified value to the end of this collection (optional operation).
`boolean`	`addAll(Collection<? extends E> c)` Appends all of the values in the specified collection to the end of this collection, in the order that they are returned by the specified collection's iterator.
`void`	`clear()` Removes all of the values from this collection (optional operation).
`boolean`	`contains(Object value)` Indicates if this collection contains the specified value.
`boolean`	`containsAll(Collection<?> c)` Indicates if this collection contains all of the values of the specified collection.
`void`	`copyTo(Collection<? super E> c)` Copies the elements from this collection into another collection.
`abstract void`	`delete(XCollection.Record record)` Deletes the specified record from this collection.
`boolean`	`equals(Object obj)` Compares the specified object with this collection for equality.
`int`	`hashCode()` Returns the hash code for this collection.
`abstract XCollection.Record`	`head()` Returns the head record of this collection; it is the record such as `head().getNext()` holds the first collection value.
`boolean`	`isEmpty()` Indicates if this collection is empty.
`XIterator<E>`	`iterator()` Returns an iterator over the elements in this collection
`boolean`	`remove(Object value)` Removes the first occurrence in this collection of the specified value (optional operation).
`boolean`	`removeAll(Collection<?> c)` Removes from this collection all the values that are contained in the specified collection.
`boolean`	`retainAll(Collection<?> c)` Retains only the values in this collection that are contained in the specified collection.
`XIterator<E>`	`reusableIterator()` Returns an iterator over the elements in this collection.
`Collection<E>`	`shared()` Returns a thread-safe read-write view of this collection.
`abstract int`	`size()` Returns the number of values in this collection.
`boolean`	`supportsIteratorModifications()` Tests if modification operations are supported for this collection's iterators.
`abstract XCollection.Record`	`tail()` Returns the tail record of this collection; it is the record such as `tail().getPrevious()` holds the last collection value.
`Object[]`	`toArray()` Returns a new array allocated on the heap containing all of the values in this collection in proper sequence.
`<T> T[]`	`toArray(T[] array)` Fills the specified array with the values of this collection in the proper sequence.
`String`	`toString()` Returns a string representation of this collection.
`Collection<E>`	`unmodifiable()` Returns the unmodifiable view associated to this collection.
`abstract E`	`valueOf(XCollection.Record record)` Returns the collection value for the specified record.

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

- Method Detail
  - size
```
public abstract int size()
```
    Returns the number of values in this collection.
    
    Specified by:
    
    size in interface Collection<E>
    
    Returns:
    the number of values.
  - head
```
public abstract XCollection.Record head()
```
    Returns the head record of this collection; it is the record such as head().getNext() holds the first collection value.
    
    Returns:
    the head record.
  - tail
```
public abstract XCollection.Record tail()
```
    Returns the tail record of this collection; it is the record such as tail().getPrevious() holds the last collection value.
    
    Returns:
    the tail record.
  - valueOf
```
public abstract E valueOf(XCollection.Record record)
```
    Returns the collection value for the specified record.
    
    Parameters:
    record - the record whose current value is returned.
    
    Returns:
    the current value.
  - delete
```
public abstract void delete(XCollection.Record record)
```
    Deletes the specified record from this collection.
    Implementation must ensure that removing a record from the collection does not affect in any way the records preceding the record being removed (it might affect the next records though, e.g. in a list collection, the indices of the subsequent records will change).
    
    Parameters:
    record - the record to be removed.
    
    Throws:
    
    UnsupportedOperationException - if not supported.
  - unmodifiable
```
public Collection<E> unmodifiable()
```
    Returns the unmodifiable view associated to this collection. Attempts to modify the returned collection result in an UnsupportedOperationException being thrown.
    
    Returns:
    the unmodifiable view over this collection.
  - shared
```
public Collection<E> shared()
```
    Returns a thread-safe read-write view of this collection.
    
    The default implementation performs synchronization on read and write. Sub-classes may provide more efficient implementation (e.g. only synchronizing on writes modifying the internal data structure).
    
    Having a shared collection does not mean that modifications made by onethread are automatically viewed by others thread. Which in practice is not an issue. In a well-behaved system, threads need to synchronize only at predetermined synchronization points (the fewer the better).
    
    Returns:
    a thread-safe collection.
  - iterator
```
public XIterator<E> iterator()
```
    Returns an iterator over the elements in this collection
    
    Specified by:
    
    iterator in interface Iterable<E>
    
    Specified by:
    
    iterator in interface Collection<E>
    
    Returns:
    an iterator over this collection's elements.
  - supportsIteratorModifications
```
public boolean supportsIteratorModifications()
```
    Tests if modification operations are supported for this collection's iterators.
    
    Returns:
    True if the iterators of this collection support the modification operations.
  - reusableIterator
```
public XIterator<E> reusableIterator()
```
    Returns an iterator over the elements in this collection. This iterator may only be used by a single thread at a time. This method invokes XIterator.toFirst() on the iterator prior to returning it.
    
    Returns:
    an iterator over this collection's elements.
  - add
```
public boolean add(E value)
```
    Appends the specified value to the end of this collection (optional operation).
    Note: This default implementation always throws UnsupportedOperationException.
    
    Specified by:
    
    add in interface Collection<E>
    
    Parameters:
    value - the value to be appended to this collection.
    
    Returns:
    true (as per the general contract of the Collection.add method).
    
    Throws:
    
    UnsupportedOperationException - if not supported.
  - remove
```
public boolean remove(Object value)
```
    Removes the first occurrence in this collection of the specified value (optional operation).
    
    Specified by:
    
    remove in interface Collection<E>
    
    Parameters:
    value - the value to be removed from this collection.
    
    Returns:
    true if this collection contained the specified value; false otherwise.
    
    Throws:
    
    UnsupportedOperationException - if not supported.
  - clear
```
public void clear()
```
    Removes all of the values from this collection (optional operation).
    
    Specified by:
    
    clear in interface Collection<E>
    
    Throws:
    
    UnsupportedOperationException - if not supported.
  - isEmpty
```
public final boolean isEmpty()
```
    Indicates if this collection is empty.
    
    Specified by:
    
    isEmpty in interface Collection<E>
    
    Returns:
    true if this collection contains no value; false otherwise.
  - contains
```
public boolean contains(Object value)
```
    Indicates if this collection contains the specified value.
    
    Specified by:
    
    contains in interface Collection<E>
    
    Parameters:
    value - the value whose presence in this collection is to be tested.
    
    Returns:
    true if this collection contains the specified value;false otherwise.
  - addAll
```
public boolean addAll(Collection<? extends E> c)
```
    Appends all of the values in the specified collection to the end of this collection, in the order that they are returned by the specified collection's iterator.
    
    Specified by:
    
    addAll in interface Collection<E>
    
    Parameters:
    c - collection whose values are to be added to this collection.
    
    Returns:
    true if this collection changed as a result of the call; false otherwise.
  - containsAll
```
public boolean containsAll(Collection<?> c)
```
    Indicates if this collection contains all of the values of the specified collection.
    
    Specified by:
    
    containsAll in interface Collection<E>
    
    Parameters:
    c - collection to be checked for containment in this collection.
    
    Returns:
    true if this collection contains all of the values of the specified collection; false otherwise.
  - removeAll
```
public boolean removeAll(Collection<?> c)
```
    Removes from this collection all the values that are contained in the specified collection.
    
    Specified by:
    
    removeAll in interface Collection<E>
    
    Parameters:
    c - collection that defines which values will be removed from this collection.
    
    Returns:
    true if this collection changed as a result of the call; false otherwise.
  - retainAll
```
public boolean retainAll(Collection<?> c)
```
    Retains only the values in this collection that are contained in the specified collection.
    
    Specified by:
    
    retainAll in interface Collection<E>
    
    Parameters:
    c - collection that defines which values this set will retain.
    
    Returns:
    true if this collection changed as a result of the call; false otherwise.
  - copyTo
```
public void copyTo(Collection<? super E> c)
```
    Copies the elements from this collection into another collection.
    
    Parameters:
    c - The collection into which this should be copied.
  - toArray
```
public Object[] toArray()
```
    Returns a new array allocated on the heap containing all of the values in this collection in proper sequence.
    Note: To avoid heap allocation toArray(Object[]) is recommended.
    
    Specified by:
    
    toArray in interface Collection<E>
    
    Returns:
    toArray(new Object[size()])
  - toArray
```
public <T> T[] toArray(T[] array)
```
    Fills the specified array with the values of this collection in the proper sequence.
    
    Specified by:
    
    toArray in interface Collection<E>
    
    Parameters:
    array - the array into which the values of this collection are to be stored.
    
    Returns:
    the specified array.
  - toString
```
public String toString()
```
    Returns a string representation of this collection. The string representation consists of a list of the collection's elements in the order they are returned by its iterator, enclosed in square brackets ("[]"). Adjacent elements are separated by the characters ", " (comma and space). Elements are converted to strings as by String.valueOf(Object).
    
    Overrides:
    
    toString in class Object
    
    Returns:
    a string representation of this collection
  - equals
```
public boolean equals(Object obj)
```
    Compares the specified object with this collection for equality. The default behavior is to consider two collections equal if they hold the same values and have the same iterative order if any of the collections is an ordered collection (List instances).
    
    Specified by:
    
    equals in interface Collection<E>
    
    Overrides:
    
    equals in class Object
    
    Parameters:
    obj - the object to be compared for equality with this collection
    
    Returns:
    true if the specified object is a collection with the same content and iteration order when necessary; false otherwise.
  - hashCode
```
public int hashCode()
```
    Returns the hash code for this collection. For non-ordered collection the hashcode of this collection is the sum of the hashcode of its values.
    
    Specified by:
    
    hashCode in interface Collection<E>
    
    Overrides:
    
    hashCode in class Object
    
    Returns:
    the hash code for this collection.

Class XCollection<E>

Nested Class Summary

Method Summary

Methods inherited from class java.lang.Object

Method Detail

size

head

tail

valueOf

delete

unmodifiable

shared

iterator

supportsIteratorModifications

reusableIterator

add

remove

clear

isEmpty

contains

addAll

containsAll

removeAll

retainAll

copyTo

toArray

toArray

toString

equals

hashCode