org.jpc.engine.embedded.database

Class IndexedClauses

java.lang.Object

org.jpc.engine.embedded.database.IndexedClauses

Direct Known Subclasses:

ClauseDatabase

public class IndexedClauses
extends Object

A repository of indexed clauses.

Author:

sergioc

Constructor Summary

Constructors

Constructor and Description
IndexedClauses()
IndexedClauses(IndexDescriptor indexDescriptor)
IndexedClauses(List<IndexDescriptor> indexDescriptors)

Method Summary

Modifier and Type	Method and Description
protected void	addClause(Clause clause)
Iterator<Clause>	indexedClausesIterator(Term head) This method answers an iterator of clauses which heads "may" unify with the parameter according to the existing indexes applicable to it.
void	reset()
void	retract(Clause clause)

Methods inherited from class java.lang.Object

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

Constructor Detail

IndexedClauses

public IndexedClauses()

IndexedClauses

public IndexedClauses(IndexDescriptor indexDescriptor)

IndexedClauses

public IndexedClauses(List<IndexDescriptor> indexDescriptors)

Method Detail

addClause

protected void addClause(Clause clause)

retract

public void retract(Clause clause)

reset

public void reset()

indexedClausesIterator

public Iterator<Clause> indexedClausesIterator(Term head)

This method answers an iterator of clauses which heads "may" unify with the parameter according to the existing indexes applicable to it. The rationale of implementing it that way instead of answering only clauses which heads unify with the argument, is to avoid duplicated unification tasks. This is because callers of this method may need to unify again the head of the clauses against the term parameter (for example, to find out the bindings of the variables in the unified term).

Parameters:

head - the term that may unify with the head of the clauses.

Returns:

an iterator of clauses which heads may unify with the given term.