de.unidu.is.pdatalog
Class Relation

java.lang.Object
  de.unidu.is.pdatalog.Relation

Direct Known Subclasses:

EDBComputedRelation, EDBRelation, IDBRelation

public abstract class Relation

extends java.lang.Object

An abstract pDatalog++ relation. This class will be extended by classes for stored relations, computed relations, derived relations etc.

Since:

2003-10-07

Version:

$Revision: 1.7 $, $Date: 2005/03/14 17:33:13 $

Author:

Henrik Nottelmann

Field Summary

protected int	arity The arity (number of arguments) of this relation.
protected RelationBase	base The corresponding relation base.
protected java.lang.String	name The relation name.

Constructor Summary

Relation(RelationBase base, java.lang.String name, int arity)
Constructs a new relation, and automatically adds it to the relation base.

Relation(RelationBase base, java.lang.String name, int arity, boolean create)
Constructs a new relation, and automatically adds it to the relation base.

Relation(java.lang.String name, int arity)
Constructs a new relation, without adding it to the relation base.

Method Summary

int	getArity() Returns the arity of this relation.
java.lang.String	getName() Returns the name of this relation.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

base

protected RelationBase base

The corresponding relation base.

name

protected java.lang.String name

The relation name.

arity

protected int arity

The arity (number of arguments) of this relation.

Constructor Detail

Relation

public Relation(java.lang.String name,
                int arity)

Constructs a new relation, without adding it to the relation base.

Parameters:

name - relatio n name

arity - arity of the relation

Relation

public Relation(RelationBase base,
                java.lang.String name,
                int arity)

Constructs a new relation, and automatically adds it to the relation base.

Parameters:

base - corresponding relation base

name - relatio n name

arity - arity of the relation

Relation

public Relation(RelationBase base,
                java.lang.String name,
                int arity,
                boolean create)

Constructs a new relation, and automatically adds it to the relation base.

Parameters:

base - corresponding relation base

name - relatio n name

arity - arity of the relation @ param create if true, the relation is physically created @ status finished 2003-12-08

Method Detail

getName

public java.lang.String getName()

Returns the name of this relation.

Returns:

name of this relation

getArity

public int getArity()

Returns the arity of this relation.

Returns:

arity of this relation

toString

public java.lang.String toString()