prolog.model
Interface IRelation

All Known Implementing Classes:

Relation

public interface IRelation

The base interface of a relation between some atoms, like a row in a database. This interface is used to store and get facts but also to store and get parameters e.g. in a statement

prolog: myFact(joe,dan).

in this example, the relation would contain the atoms "joe" and "dan"

Method Summary

java.util.Map	buildMap() builds a indexmap. a indexmap contains the atom as key and the index as integer. this function is only used for parameter matching.
void	genXml(java.io.Writer out, ISymbolTable table) generates xml describing this relation
IAtom	get(int index) returns the atom at the specified index
int	getValueCount() returns the number of atoms contained in this relation
java.util.Iterator	getValues() returns an iterator over all atoms contained in this relation
java.lang.String	toString(int[] parameterNames, ISymbolTable table) returns a string representation of this object with decoded symbols in prolog syntax used for query results e.g.
java.lang.String	toString(ISymbolTable table) returns a string representation of this object with decoded symbols

Method Detail

getValueCount

public int getValueCount()

returns the number of atoms contained in this relation

Returns:

number of atoms

get

public IAtom get(int index)

returns the atom at the specified index

Parameters:

index - of the atom to be returned

Returns:

atom at the specified index

getValues

public java.util.Iterator getValues()

returns an iterator over all atoms contained in this relation

Returns:

iterator over the values in this relation

buildMap

public java.util.Map buildMap()

builds a indexmap. a indexmap contains the atom as key and the index as integer. this function is only used for parameter matching.

Returns:

the created indexmap

genXml

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

generates xml describing this relation

Parameters:

out - the writer where o append the xml

table - the symboltable if the xml should be decoded

Throws:

java.io.IOException - if writing xml fails

toString

public java.lang.String toString(ISymbolTable table)

returns a string representation of this object with decoded symbols

Parameters:

table - - the symboltable used to decode

Returns:

the string representation

toString

public java.lang.String toString(int[] parameterNames,
                                 ISymbolTable table)

returns a string representation of this object with decoded symbols in prolog syntax used for query results e.g. X=a, Y=b

Parameters:

table - - the symboltable used to decode

parameterNames - - the names of the parameters in this relation

Returns:

the string representation