prolog.implementation
Class FactList

java.lang.Object
  |
  +--prolog.implementation.FactList

All Implemented Interfaces:

IFact, IFactList

public class FactList

extends java.lang.Object

implements IFactList

FactList is the base implementation for a collection of relations. It can be compared with a database table containing rows of relations. The name of the factlist would be the tablename. That's why factlist extends IFact. So it inherits a name. The relation of the extended IFact are also used for factlists returned by queries. In this relation, parameters of the statements are stored.

prolog:

myFact(joe,dan).

myFact(joe,dan2).

In this example, the two facts "myFact" are stored in a factlist.

interpreter internal:

myFact(joe,dan).

myFact(joe,dan2).

myStatement(X,Y):-myFact(X,Y).

In this example, the results returned by myFact(X,Y) are stored in a factlist.

Field Summary

protected int	colCount stores the number of columns stored in this factlist
protected java.util.List	facts stores the relations
protected int	name stores the name of this fact list
protected Relation	relation stores the parameters of this fact list

Constructor Summary

FactList(FactList list)
copy constructor

FactList(int name, int colCount)
bean constructor

Method Summary

void	addAttribute(java.lang.Object value) adds a attribute to the relation
void	addRelation(IRelation relation) adds a relation to this factlist
void	genXml(java.io.Writer out, ISymbolTable table) generates a xml representation of this class
int	getColCount()
IFactList	getCopy()
IFactList	getMatchings(IFact fact) returns a new factlist with facts matching this given fact
int	getName() returns the name of this fact
IRelation	getRelation() returns the relalation this fact owns
java.util.Iterator	getRelations()
int	getRowCount()
void	setRelation(IRelation relation) sets the relation format of this factlist
java.lang.String	toString()
java.lang.String	toString(ISymbolTable table) returns a string representation of this oject, if the parameter ISymbolTable is specified, the symbols are decoded

Methods inherited from class java.lang.Object

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

Field Detail

relation

protected Relation relation

stores the parameters of this fact list

name

protected int name

stores the name of this fact list

colCount

protected int colCount

stores the number of columns stored in this factlist

facts

protected java.util.List facts

stores the relations

Constructor Detail

FactList

public FactList(int name,
                int colCount)

bean constructor

Parameters:

name - is the name of this factlist

FactList

public FactList(FactList list)

copy constructor

Parameters:

list - to copy

Method Detail

addAttribute

public void addAttribute(java.lang.Object value)

adds a attribute to the relation

Parameters:

value - is the attribute to be added

getName

public int getName()

Description copied from interface: IFact

returns the name of this fact

Specified by:

getName in interface IFact

Returns:

the name of this factlist

getColCount

public int getColCount()

Specified by:

getColCount in interface IFactList

Returns:

the number of columns stored in this factlist

getRowCount

public int getRowCount()

Specified by:

getRowCount in interface IFactList

Returns:

the number of relations in this factlist

setRelation

public void setRelation(IRelation relation)

sets the relation format of this factlist

Specified by:

setRelation in interface IFactList

Parameters:

relation -

getRelation

public IRelation getRelation()

Description copied from interface: IFact

returns the relalation this fact owns

Specified by:

getRelation in interface IFact

Returns:

the relation of this factlist. in this relation, the variablen names of this factlist are contained

addRelation

public void addRelation(IRelation relation)

adds a relation to this factlist

Specified by:

addRelation in interface IFactList

Following copied from interface: prolog.model.IFactList

Parameters:

atoms - to be added

getRelations

public java.util.Iterator getRelations()

Specified by:

getRelations in interface IFactList

Returns:

a iterator over all relations contained in this class

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

Returns:

a string representation of this class

toString

public java.lang.String toString(ISymbolTable table)

Description copied from interface: IFact

returns a string representation of this oject, if the parameter ISymbolTable is specified, the symbols are decoded

Specified by:

toString in interface IFact

Parameters:

table - is the ISymbolTable required to decode the symbols

Returns:

a string representation of this class with decoded symbols

genXml

public void genXml(java.io.Writer out,
                   ISymbolTable table)
            throws java.io.IOException

generates a xml representation of this class

Specified by:

genXml in interface IFact

Parameters:

out - the writer to append the xml

table - is the ISymbolTable to decode the symbols

Throws:

java.io.IOException -

getCopy

public IFactList getCopy()

Specified by:

getCopy in interface IFactList

Returns:

a copy of this class

getMatchings

public IFactList getMatchings(IFact fact)
                       throws ParameterMatchingError

returns a new factlist with facts matching this given fact

Specified by:

getMatchings in interface IFactList

Parameters:

fact - is the fact to search for

Returns: