de.lmu.ifi.dbs.elki.database.ids

Class EmptyDBIDs

java.lang.Object

de.lmu.ifi.dbs.elki.database.ids.EmptyDBIDs

All Implemented Interfaces:

ArrayDBIDs, ArrayStaticDBIDs, DBIDs, SetDBIDs, StaticDBIDs

public class EmptyDBIDs
extends java.lang.Object
implements ArrayStaticDBIDs, SetDBIDs

Empty DBID collection.

Since:

0.4.0

Author:

Erich Schubert

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	EmptyDBIDs.EmptyDBIDIterator Iterator for empty DBIDs-

Field Summary

Fields

Modifier and Type	Field and Description
static EmptyDBIDs.EmptyDBIDIterator	EMPTY_ITERATOR Empty DBID iterator.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	EmptyDBIDs() Constructor.

Method Summary

Modifier and Type	Method and Description
DBIDVar	assignVar(int index, DBIDVar var) Assign a DBID variable the value of position index.
int	binarySearch(DBIDRef key) Search for the position of the given key, assuming that the data set is sorted.
boolean	contains(DBIDRef o) Test whether an ID is contained.
void	forEach(java.util.function.Consumer<? super DBIDRef> action) Execute a function for each ID.
DBID	get(int i) Get the i'th entry (starting at 0) If possible, use an DBIDArrayIter via ArrayDBIDs.iter() instead, or an DBIDVar via ArrayDBIDs.assignVar(int, de.lmu.ifi.dbs.elki.database.ids.DBIDVar)
boolean	isEmpty() Test for an empty DBID collection.
DBIDArrayMIter	iter() Iterable
int	size() Size of the DBID "collection".
ArrayDBIDs	slice(int begin, int end) Slice a subarray (as view, not copy!)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

EMPTY_ITERATOR

public static final EmptyDBIDs.EmptyDBIDIterator EMPTY_ITERATOR

Empty DBID iterator.

Constructor Detail

EmptyDBIDs

protected EmptyDBIDs()

Constructor.

Method Detail

contains

public boolean contains(DBIDRef o)

Description copied from interface: DBIDs

Test whether an ID is contained.

Specified by:

contains in interface DBIDs

Parameters:

o - object to test

Returns:

true when contained

size

public int size()

Description copied from interface: ArrayDBIDs

Size of the DBID "collection".

Specified by:

size in interface ArrayDBIDs

Specified by:

size in interface DBIDs

Returns:

size

isEmpty

public boolean isEmpty()

Description copied from interface: DBIDs

Test for an empty DBID collection.

Specified by:

isEmpty in interface DBIDs

Returns:

true when empty.

get

public DBID get(int i)

Description copied from interface: ArrayDBIDs

Get the i'th entry (starting at 0)

If possible, use an DBIDArrayIter via ArrayDBIDs.iter() instead, or an DBIDVar via ArrayDBIDs.assignVar(int, de.lmu.ifi.dbs.elki.database.ids.DBIDVar)

Specified by:

get in interface ArrayDBIDs

Parameters:

i - Index

Returns:

DBID of i'th entry.

assignVar

public DBIDVar assignVar(int index,
                         DBIDVar var)

Description copied from interface: ArrayDBIDs

Assign a DBID variable the value of position index.

Specified by:

assignVar in interface ArrayDBIDs

Parameters:

index - Position

var - Variable to assign the value to.

iter

public DBIDArrayMIter iter()

Description copied from interface: ArrayDBIDs

Iterable

Specified by:

iter in interface ArrayDBIDs

Specified by:

iter in interface DBIDs

Returns:

Iterator

binarySearch

public int binarySearch(DBIDRef key)

Description copied from interface: ArrayDBIDs

Search for the position of the given key, assuming that the data set is sorted. For unsorted arrays, the result is undefined.

For keys not found, -(1+insertion position) is returned, as for Java Collections.binarySearch(java.util.List<? extends java.lang.Comparable<? super T>>, T)

Specified by:

binarySearch in interface ArrayDBIDs

Parameters:

key - Key to search for

Returns:

Offset of key

slice

public ArrayDBIDs slice(int begin,
                        int end)

Description copied from interface: ArrayDBIDs

Slice a subarray (as view, not copy!)

Specified by:

slice in interface ArrayDBIDs

Parameters:

begin - Begin (inclusive)

end - End (exclusive)

Returns:

Array slice.

forEach

public void forEach(java.util.function.Consumer<? super DBIDRef> action)

Description copied from interface: DBIDs

Execute a function for each ID.

Specified by:

forEach in interface DBIDs

Parameters:

action - Action to execute