Index (Javolution Backport 5.6.9 API)

java.lang.Object
- java.lang.Number
- - javolution.util.Index

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<Index>, Immutable, Realtime, FastCollection.Record, XMLSerializable
```
public final class Index
extends java.lang.Number
implements java.lang.Comparable<Index>, FastCollection.Record, Realtime, Immutable, XMLSerializable
```
This class represents a unique index which can be used instead of java.lang.Integer for primitive data types collections. For example:
```
         class SparseVector<F> {
             FastMap<Index, F> _elements = new FastMap<Index, F>();
             ...
         }
```
Unicity is guaranteed and direct equality (==) can be used in place of object equality (Index.equals(Object)).

Indices have no adverse effect on the garbage collector (persistent instances), but should not be used for large integer values as that would increase the permanent memory footprint significantly.

RTSJ: Instance of this classes are allocated in ImmortalMemory. Indices can be pre-allocated at start-up to avoid run-time allocation delays by configuring INITIAL_FIRST and/or INITIAL_LAST or through setMinimumRange(int, int).
Version:

5.1, July 26, 2007

Author:

Jean-Marie Dautelle

See Also:

Serialized Form

Field Summary

Fields
Modifier and Type	Field and Description
`static Configurable<java.lang.Integer>`	`INITIAL_FIRST` Holds the initial first index value (default `-1`).
`static Configurable<java.lang.Integer>`	`INITIAL_LAST` Holds the initial last index value (default `31`).
`static Index`	`ZERO` Holds the index zero (value `0`).

Method Summary

All Methods Static Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`compareTo(Index that)`
`double`	`doubleValue()` Returns the index value as `int`.
`boolean`	`equals(java.lang.Object obj)` Indicates if this index is equals to the one specified (unicity ensures that this method is equivalent to `==`).
`float`	`floatValue()` Returns the index value as `float`.
`FastCollection.Record`	`getNext()` Returns the record after this one.
`FastCollection.Record`	`getPrevious()` Returns the record before this one.
`int`	`hashCode()` Returns the hash code for this index.
`int`	`intValue()` Returns the index value as `int`.
`long`	`longValue()` Returns the index value as `long`.
`static java.util.List<Index>`	`rangeOf(int start, int end)` Returns all the indices greater or equal to `start` but less than `end`.
`protected java.lang.Object`	`readResolve()` Ensures index unicity during deserialization.
`static void`	`setMinimumRange(int first, int last)` Creates the indices for the specified range of values if they don't exist.
`java.lang.String`	`toString()` Returns the `String` representation of this index.
`Text`	`toText()` Returns the textual representation of this real-time object (equivalent to `toString` except that the returned value can be `"stack"` allocated and supports fast concatenation).
`static Index`	`valueOf(int i)` Returns the unique index for the specified `int` value (creating it as well as the indices toward `zero` if they do not exist).
`static java.util.List<Index>`	`valuesOf(int... indices)` Returns the list of all the indices specified.

Methods inherited from class java.lang.Number
byteValue, shortValue

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

- Field Detail
  - ZERO
```
public static final Index ZERO
```
    Holds the index zero (value 0).
  - INITIAL_FIRST
```
public static final Configurable<java.lang.Integer> INITIAL_FIRST
```
    Holds the initial first index value (default -1).
  - INITIAL_LAST
```
public static final Configurable<java.lang.Integer> INITIAL_LAST
```
    Holds the initial last index value (default 31).
- Method Detail
  - setMinimumRange
```
public static void setMinimumRange(int first,
                                   int last)
```
    Creates the indices for the specified range of values if they don't exist.
    
    Parameters:
    
    first - the first index value.
    
    last - the last index value.
    
    Throws:
    
    java.lang.IllegalArgumentException - if first > last
  - valueOf
```
public static Index valueOf(int i)
```
    Returns the unique index for the specified int value (creating it as well as the indices toward zero if they do not exist).
    
    Parameters:
    
    i - the index value.
    
    Returns:
    
    the corresponding unique index.
  - rangeOf
```
public static java.util.List<Index> rangeOf(int start,
                                            int end)
```
    Returns all the indices greater or equal to start but less than end.
    
    Parameters:
    
    start - the start index.
    
    end - the end index.
    
    Returns:
    
    [start .. end[
  - valuesOf
```
public static java.util.List<Index> valuesOf(int... indices)
```
    Returns the list of all the indices specified.
    
    Parameters:
    
    indices - the indices values.
    
    Returns:
    
    {indices[0], indices[1], ...}
  - intValue
```
public int intValue()
```
    Returns the index value as int.
    
    Specified by:
    
    intValue in class java.lang.Number
    
    Returns:
    
    the index value.
  - longValue
```
public long longValue()
```
    Returns the index value as long.
    
    Specified by:
    
    longValue in class java.lang.Number
    
    Returns:
    
    the index value.
  - floatValue
```
public float floatValue()
```
    Returns the index value as float.
    
    Specified by:
    
    floatValue in class java.lang.Number
    
    Returns:
    
    the index value.
  - doubleValue
```
public double doubleValue()
```
    Returns the index value as int.
    
    Specified by:
    
    doubleValue in class java.lang.Number
    
    Returns:
    
    the index value.
  - toString
```
public java.lang.String toString()
```
    Returns the String representation of this index.
    
    Overrides:
    
    toString in class java.lang.Object
    
    Returns:
    
    TextFormat.getInstance(Cursor.class).formatToString(_value)
  - equals
```
public final boolean equals(java.lang.Object obj)
```
    Indicates if this index is equals to the one specified (unicity ensures that this method is equivalent to ==).
    
    Overrides:
    
    equals in class java.lang.Object
    
    Returns:
    
    this == obj
  - hashCode
```
public final int hashCode()
```
    Returns the hash code for this index.
    
    Overrides:
    
    hashCode in class java.lang.Object
    
    Returns:
    
    the index value.
  - readResolve
```
protected final java.lang.Object readResolve()
                                      throws java.io.ObjectStreamException
```
    Ensures index unicity during deserialization.
    
    Returns:
    
    the unique instance for this deserialized index.
    
    Throws:
    
    java.io.ObjectStreamException
  - compareTo
```
public final int compareTo(Index that)
```
    Specified by:
    
    compareTo in interface java.lang.Comparable<Index>
  - getNext
```
public final FastCollection.Record getNext()
```
    Description copied from interface: FastCollection.Record
    
    Returns the record after this one.
    
    Specified by:
    
    getNext in interface FastCollection.Record
    
    Returns:
    
    the next record.
  - getPrevious
```
public final FastCollection.Record getPrevious()
```
    Description copied from interface: FastCollection.Record
    
    Returns the record before this one.
    
    Specified by:
    
    getPrevious in interface FastCollection.Record
    
    Returns:
    
    the previous record.
  - toText
```
public Text toText()
```
    Description copied from interface: Realtime
    
    Returns the textual representation of this real-time object (equivalent to toString except that the returned value can be "stack" allocated and supports fast concatenation).
    
    Specified by:
    
    toText in interface Realtime
    
    Returns:
    
    this object's textual representation.

Class Index

Field Summary

Method Summary

Methods inherited from class java.lang.Number

Methods inherited from class java.lang.Object

Field Detail

ZERO

INITIAL_FIRST

INITIAL_LAST

Method Detail

setMinimumRange

valueOf

rangeOf

valuesOf

intValue

longValue

floatValue

doubleValue

toString

equals

hashCode

readResolve

compareTo

getNext

getPrevious

toText