Package monq.jfa

Class Intervals<D>

java.lang.Object

monq.jfa.Intervals<D>

public class Intervals<D>
extends Object

Used to construct CharTrans objects of different implementations.

NOTE: This looks as if it could implement CharTrans, but it should not, because it explicitly stores character ranges mapped to null which contradicts the contract of CharTrans. Furthermore this class is intentionally mutable, which is also not the idea of CharTrans.

TODO: replace with an implementation which has a complete Char.MAX_VALUE pair of arrays that is plainly set and overwritten, instead of mainting the intervals. Then measure performance.

Constructor Summary

Constructors

Constructor	Description
Intervals()

Method Summary

Modifier and Type	Method	Description
final void	complete(D o)	all intervals which are currently mapped to null will be mapped to the given object.
D	get(char ch)
final D	getAt(int i)
final char	getFirstAt(int i)
final char	getLastAt(int i)
final void	invert(D o)	inverts the mapped and unmapped intervals.
static String	logStats()
final void	overwrite(char first, char last, D o)
final void	reset()	reset to the state of a freshly constructed object.
static void	resetStats()
final void	setAt(int i, D o)
final int	size()	Provides the number of stored character ranges, including ranges which map to null.
String	toString()
final <E> void	update(char first, char last, E newValue, Function<D,D> copyOnSplit, BiFunction<D,E,D> merger)	Update what the range of characters from first to last (inclusive) maps to by applying the merger to the currently mapped value and the new one.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Details

Intervals

public Intervals()

Method Details

logStats

public static String logStats()

resetStats

public static void resetStats()

complete

public final void complete(D o)

all intervals which are currently mapped to null will be mapped to the given object.

reset

public final void reset()

reset to the state of a freshly constructed object. In particular there will be one interval spanning the whole range of char values being mapped to null.

get

public D get(char ch)

size

public final int size()

Provides the number of stored character ranges, including ranges which map to null. For Example, after a reset() this is 1, because the single stored character range including all characters is mapped to null. After adding a value for one range, say, a-z, this will be 3, with the range left right of [a-z] mapped to null.

Returns:

number of store character ranges, including those mapped to null

getAt

public final D getAt(int i)

setAt

public final void setAt(int i,
 D o)

getFirstAt

public final char getFirstAt(int i)

getLastAt

public final char getLastAt(int i)

overwrite

public final void overwrite(char first,
 char last,
 D o)

update

public final <E> void update(char first,
 char last,
 E newValue,
 Function<D,D> copyOnSplit,
 BiFunction<D,E,D> merger)

Update what the range of characters from first to last (inclusive) maps to by applying the merger to the currently mapped value and the new one.

As an example consider the stored values to be of type D=Set<Stuff> and the newValue of type Stuff where the merger adds the new value to the set.

Type Parameters:

E - type of the new value

Parameters:

first - character of range

last - character of range

newValue - to merge with available values.

copyOnSplit - when splitting an available interval at either first or last, the newly introduced interval needs a value and copyOnSplit is called with the value of the previous interval. It may just return that value, or make a copy, or return a fresh value or null or whatever is needed

merger - merge the available value in the range with the new value. NOTE: the merger must deal with the available value being null

invert

public final void invert(D o)

inverts the mapped and unmapped intervals. Intervals which are currently mapped to null will be mapped to o, and those currently mapped to some object are mapped to null.

toString

public String toString()

Overrides:

toString in class Object