Package it.unimi.dsi.big.util

Class TernaryIntervalSearchTree

java.lang.Object

it.unimi.dsi.fastutil.objects.AbstractObject2LongFunction<CharSequence>

it.unimi.dsi.big.util.AbstractPrefixMap

it.unimi.dsi.big.util.TernaryIntervalSearchTree

All Implemented Interfaces:

PrefixMap<MutableString>, StringMap<MutableString>, Function<CharSequence,Long>, Object2LongFunction<CharSequence>, Size64, Serializable, Function<CharSequence,Long>, ToLongFunction<CharSequence>

public class TernaryIntervalSearchTree
extends AbstractPrefixMap
implements Serializable

Ternary interval search trees.

Ternary search trees are a data structure used to store words over an alphabet; they are a useful alternatives to tries when the alphabet is large.

Ternary interval search trees have the additional properties of being able to locate quickly intervals of words extending a given prefix (where “quickly” means that no more successful character comparisons than the prefix length are performed). They do so by storing at each node the number of words covered by that node.

This implementation exposes a number of interfaces: in particular, the set of words is seen as a lexicographically ordered ObjectList.

This class is mutable, but for the time it implements only add(CharSequence). Words cannot be removed.

Since:

2.0

See Also:

Serialized Form

Field Summary

Fields inherited from class it.unimi.dsi.big.util.AbstractPrefixMap

list, prefixMap, rangeMap

Fields inherited from class it.unimi.dsi.fastutil.objects.AbstractObject2LongFunction

defRetValue

Constructor Summary

Constructors

Constructor	Description
TernaryIntervalSearchTree()	Creates a new empty ternary search tree.
TernaryIntervalSearchTree(Collection<? extends CharSequence> c)	Creates a new empty ternary search tree and populates it with a given collection of character sequences.

Method Summary

Modifier and Type	Method	Description
boolean	add(CharSequence s)
boolean	containsKey(Object o)
LongInterval	getApproximatedInterval(CharSequence s)
protected long	getIndex(CharSequence s)
protected LongInterval	getInterval(CharSequence s)	Returns the range of strings having a given prefix.
long	getLong(Object o)
protected MutableString	getTerm(long index, MutableString s)	Writes a string specified by index into a MutableString.
static void	main(String[] arg)
int	size()	Deprecated.
long	size64()	Returns the intended number of keys in this function, or -1 if no such number exists.

Methods inherited from class it.unimi.dsi.big.util.AbstractPrefixMap

list, prefixMap, rangeMap

Methods inherited from class it.unimi.dsi.fastutil.objects.AbstractObject2LongFunction

defaultReturnValue, defaultReturnValue

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unimi.dsi.fastutil.Function

apply, clear

Methods inherited from interface java.util.function.Function

andThen, compose

Methods inherited from interface it.unimi.dsi.fastutil.objects.Object2LongFunction

applyAsLong, defaultReturnValue, defaultReturnValue, get, put, put, remove, removeLong

Constructor Detail

TernaryIntervalSearchTree

public TernaryIntervalSearchTree()

Creates a new empty ternary search tree.

TernaryIntervalSearchTree

public TernaryIntervalSearchTree(Collection<? extends CharSequence> c)

Creates a new empty ternary search tree and populates it with a given collection of character sequences.

Parameters:

c - a collection of character sequences.

Method Detail

getInterval

protected LongInterval getInterval(CharSequence s)

Description copied from class: AbstractPrefixMap

Returns the range of strings having a given prefix.

Specified by:

getInterval in class AbstractPrefixMap

Parameters:

s - a prefix.

Returns:

the corresponding range of strings as an interval.

getApproximatedInterval

public LongInterval getApproximatedInterval(CharSequence s)

getTerm

protected MutableString getTerm(long index,
                                MutableString s)

Description copied from class: AbstractPrefixMap

Writes a string specified by index into a MutableString.

Specified by:

getTerm in class AbstractPrefixMap

Parameters:

index - the index of a string.

s - a mutable string.

Returns:

string.

getIndex

protected long getIndex(CharSequence s)

containsKey

public boolean containsKey(Object o)

Specified by:

containsKey in interface Function<CharSequence,Long>

getLong

public long getLong(Object o)

Specified by:

getLong in interface Object2LongFunction<CharSequence>

add

public boolean add(CharSequence s)

size

@Deprecated
public int size()

Deprecated.

Description copied from interface: StringMap

Specified by:

size in interface Function<CharSequence,Long>

Specified by:

size in interface Size64

Specified by:

size in interface StringMap<MutableString>

size64

public long size64()

Description copied from interface: StringMap

Returns the intended number of keys in this function, or -1 if no such number exists.

Most function implementations will have some knowledge of the intended number of keys in their domain. In some cases, however, this might not be possible. This default implementation, in particular, returns -1.

Specified by:

size64 in interface Size64

Specified by:

size64 in interface StringMap<MutableString>

Returns:

the intended number of keys in this function, or -1 if that number is not available.

main

public static void main(String[] arg)
                 throws IOException,
                        JSAPException,
                        NoSuchMethodException

Throws:

IOException

JSAPException

NoSuchMethodException