Package edu.upc.fib.inlab.imp.kse.logics.logicschema.domain

Class LevelHierarchy

java.lang.Object

edu.upc.fib.inlab.imp.kse.logics.logicschema.domain.LevelHierarchy

All Implemented Interfaces:

Iterable<Level>

public class LevelHierarchy
extends Object
implements Iterable<Level>

This class implements the definition of hierarchical database as defined in "Basis for Deductive Database Systems" by J. W. Lloyd AND R. W. Topor.

A database is called hierarchical if its predicates can be partitioned into levels so that the definitions of level 0 predicates consist solely of base predicates and the bodies of the derived predicates of level j contain only level i predicates, where i < j.

Constructor Summary

Constructors

Constructor	Description
LevelHierarchy(List<Level> levels)

Method Summary

Modifier and Type	Method	Description
void	forEach(Consumer<? super Level> action)
Level	getBasePredicatesLevel()
List<Level>	getDerivedLevels()
Level	getLevel(int index)
int	getLevelIndexOfPredicate(Predicate predicate)	May throw exception if predicate is not contained in the hierarchy
Level	getLevelOfPredicate(Predicate predicate)	May throw exception if predicate is not contained in the hierarchy
int	getNumberOfLevels()
Iterator<Level>	iterator()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

spliterator

Constructor Details

LevelHierarchy

public LevelHierarchy(List<Level> levels)

Method Details

getNumberOfLevels

public int getNumberOfLevels()

getLevel

public Level getLevel(int index)

getLevelIndexOfPredicate

public int getLevelIndexOfPredicate(Predicate predicate)

May throw exception if predicate is not contained in the hierarchy

Parameters:

predicate - a non-null predicate

Returns:

the index of the predicate

getLevelOfPredicate

public Level getLevelOfPredicate(Predicate predicate)

May throw exception if predicate is not contained in the hierarchy

Parameters:

predicate - a non-null predicate

Returns:

the level of the predicate

getBasePredicatesLevel

public Level getBasePredicatesLevel()

Returns:

the 0-th level of the hierarchy, which contains the base predicates

getDerivedLevels

public List<Level> getDerivedLevels()

Returns:

a list with the levels representing derived predicates (i.e., i-th levels with i > 0)

iterator

public Iterator<Level> iterator()

Specified by:

iterator in interface Iterable<Level>

forEach

public void forEach(Consumer<? super Level> action)

Specified by:

forEach in interface Iterable<Level>