ubc.cs.JLog.Terms.jPredicateTerms Maven / Gradle / Ivy

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/*
    This file is part of JLog.

    Created by Glendon Holst for Alan Mackworth and the 
    "Computational Intelligence: A Logical Approach" text.
    
    Copyright 1998, 2000, 2002 by University of British Columbia and 
    Alan Mackworth.
    
    This notice must remain in all files which belong to, or are derived 
    from JLog.
    
    Check  or 
     for further information
    about JLog, or to contact the authors.
     
    JLog is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    JLog is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with JLog; if not, write to the Free Software
    Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    URLs:  or 
*/
//#########################################################################
//	PredicateTerms
//#########################################################################

package ubc.cs.JLog.Terms;

import java.lang.*;
import java.util.*;
import ubc.cs.JLog.Foundation.*;
import ubc.cs.JLog.Builtins.*;

/**
* This class represents a collection of predicates.
* 
* @author       Glendon Holst
* @version      %I%, %G%
*/
public class jPredicateTerms extends jCompoundTerm
{
 public jPredicateTerms()
 {
  super();
  type = TYPE_PREDICATETERMS;
 };

 protected jPredicateTerms(Vector t)
 {
  super(t);
  type = TYPE_PREDICATETERMS;
 };

 public void 			addTerm(jTerm t)
 {
  addPredicate((iPredicate) t); 
 };
 
 public void 			removeTerm(jTerm t)
 {
  removePredicate((iPredicate) t);
 };
 
 public void 			addPredicate(iPredicate p)
 {
  super.addTerm(p); 
 };
 
 public void 			removePredicate(iPredicate p)
 {
  super.removeTerm(p);
 };
 
 public jTerm 		duplicate(jVariable[] vars)
 {  
  return new jPredicateTerms(internal_duplicate(vars));
 };
 
 public jTerm 		copy(jVariableRegistry vars)
 {
  return new jPredicateTerms(internal_copy(vars));
 };

 public void  		addGoals(jGoal g,jVariable[] vars,iGoalStack goals)
 {int 		i;

  for (i = terms.size() - 1; i >= 0; i--)
   ((iPredicate) terms.elementAt(i)).addGoals(g,vars,goals);
 };

 public void  		addGoals(jGoal g,iGoalStack goals)
 {int 		i;

  for (i = terms.size() - 1; i >= 0; i--)
   ((iPredicate) terms.elementAt(i)).addGoals(g,goals);
 };

 protected String 	getStartingSymbol()
 {
  return "";
 }; 
 
 protected String 	getEndingSymbol()
 {
  return "";
 }; 
 
 /**
  * Makes this a representation of the provided jTerm, which may include
  * conjunction and disjunction operators. Invokes makePredicateTerms.
  *
  * @param t		jTerm using jCons to separate 
  * 			terms.
  */
 public void 			make(jTerm t)
 {
  removeAllTerms();
  makePredicateTerms(t);
 };
 
 /**
  * Add jCons and jOr separated jTerms 
  * to this jPredicateTerms.
  *
  * @param t		jTerm using jCons and/or 
  * 			jOr to separate terms.
  */
 public void 			makePredicateTerms(jTerm t)
 {
  if (t instanceof jPredicateTerms)
  {jPredicateTerms 		pterm = (jPredicateTerms) t;
   Enumeration 			e = pterm.enumTerms();
   
   while (e.hasMoreElements())
    addPredicate((iPredicate) e.nextElement());
  }
  else if (t instanceof jOr)
  {jOrPredicate 		jop = new jOrPredicate();
  
   addPredicate(jop);
   makeOrPredicateTerms(jop,t);
  }
  else
   makeConsPredicateTerms(t);
 };

 /**
  * Add jOr separated jTerms to the provided  
  * jOrPredicate.
  *
  * @param orpred	The jOrPredicate to add the jOr
  * 			separated jTerms to.
  * @param term		jTerm using jOr to separate terms.
  */
 protected void 		makeOrPredicateTerms(jOrPredicate orpred,jTerm term)
 {jTerm 				current = term;
  jPredicateTerms 		pterm;

  while (current instanceof jOr)
  {jTerm 	t = ((jOr) current).getLHS();
  
   if (t instanceof jOr)
    makeOrPredicateTerms(orpred,t);
   else
   {
    pterm = new jPredicateTerms();
    pterm.makeConsPredicateTerms(t);
    orpred.addPredicateTerms(pterm);
   }
   current = ((jOr) current).getRHS();
  }
 
  if (current != null)
  {
   pterm = new jPredicateTerms();
   pterm.makeConsPredicateTerms(current);
   orpred.addPredicateTerms(pterm);
  }
 };
 
 /**
  * Add jCons separated jTerms to this  
  * jPredicateTerms instance.
  *
  * @param term		jTerm using jOr to separate terms.
  */
 protected void 		makeConsPredicateTerms(jTerm term)
 {
  if (term instanceof jCons)
  {
   makePredicateTerms(((jCons) term).getLHS()); 
   makePredicateTerms(((jCons) term).getRHS());
  }
  else if (term instanceof iPredicate)
   addPredicate((iPredicate) term);
  else if (term instanceof jVariable)
   addPredicate(new jCall(term));
  else if (term != null)
   throw new PredicateExpectedException("Expected term to be a predicate or variable.",term); 
 };
 
 /**
  * Creates a jCons and/or jOr separated jTerms 
  * to represent this jPredicateTerms. Invokes 
  * unmakePredicateTerms to perform work.
  *
  * @return		jTerm using jCons and jOr
  * 			to separate terms. Duplicates this jPredicateTerms.
  */
 public jTerm 			unmake()
 {
  return unmakePredicateTerms();
 };
 
 /**
  * Creates a jCons and/or jOr separated jTerms 
  * to represent this jPredicateTerms. 
  *
  * @return		jTerm using jCons and jOr
  * 			to separate terms. Duplicates this jPredicateTerms.
  */
 public synchronized jTerm 			unmakePredicateTerms()
 {int 		i;
  jTerm 	prev = null;
 
  for (i = terms.size() - 1; i >= 0; i--)
  {iPredicate 	curr = (iPredicate) terms.elementAt(i);
   jTerm 		next;
   
   if (curr instanceof iMakeUnmake)
    next = ((iMakeUnmake) curr).unmake();
   else
    next = curr;
    
   if (prev == null)
    prev = next;
   else
    prev = new jCons(next,prev);
  }
  return prev;
 };
};