Package owl.collections

Class IntPreOrder

java.lang.Object

owl.collections.IntPreOrder

public class IntPreOrder
extends Object

This class represents a total pre-orders of {1,..n}, which are identified by a list of their equivalence classes.

This domain has a canonical lattice structure induced by the "granularity" - a total pre-order refines another if it induces smaller equivalence classes. The top element is the most granular pre-order, whose only equivalence class is the full domain. The bottom elements are all total orders (i.e. they also are antisymmetric).

The class provides two operations:

• generation(java.util.Set<java.lang.Integer>): Computes the record obtained by "rebirth" of the given elements, i.e. they are defined as the new first equivalence class.
• refines(IntPreOrder): Determines whether this record is strict refinement of the other record.

This class is imported from https://github.com/incaseoftrouble/naturals-util

Field Summary

Fields

Modifier and Type	Field	Description
protected int[][]	array
protected int	size

Method Summary

Modifier and Type	Method	Description
int	classes()	Returns the number of classes.
static IntPreOrder	coarsest(int n)	Returns the coarsest pre-order over the {1,..,n} domain, i.e.
static IntPreOrder	empty()	Returns the empty pre-order.
boolean	equals(Object o)
int[]	equivalenceClass(int index)	Returns the class with the given index.
static IntPreOrder	finest(int n)	Returns a finest pre-order over the {1,..,n} domain, i.e.
IntPreOrder	generation(Set<Integer> newborn)	Computes the pre-order obtained by declaring newborn as the smallest elements.
int	hashCode()
boolean	refines(IntPreOrder other)	Determines whether the pre-order defined by this object strictly refines the other.
int	size()	Returns the domain size.
String	toString()

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

array

protected final int[][] array

size

protected final int size

Method Detail

coarsest

public static IntPreOrder coarsest(int n)

Returns the coarsest pre-order over the {1,..,n} domain, i.e. [{1,..,n}].

Parameters:

n - The size of the domain

Returns:

The coarsest record over the domain

empty

public static IntPreOrder empty()

Returns the empty pre-order.

finest

public static IntPreOrder finest(int n)

Returns a finest pre-order over the {1,..,n} domain, i.e. a record of the form [{1},{2},..,{n}].

classes

public int classes()

Returns the number of classes.

equals

public boolean equals(Object o)

Overrides:

equals in class Object

equivalenceClass

public int[] equivalenceClass(int index)

Returns the class with the given index.

Warning: For performance reasons, the internal array is returned (instead of a copy). This array must not be modified.

generation

public IntPreOrder generation(Set<Integer> newborn)

Computes the pre-order obtained by declaring newborn as the smallest elements.

Parameters:

newborn - The new smallest elements.

Returns:

The pre-order with newborn as new smallest elements.

hashCode

public int hashCode()

Overrides:

hashCode in class Object

refines

public boolean refines(IntPreOrder other)

Determines whether the pre-order defined by this object strictly refines the other.

size

public int size()

Returns the domain size.

toString

public String toString()

Overrides:

toString in class Object