/*
 * Copyright (c) 2005, Regents of the University of California
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in
 *   the documentation and/or other materials provided with the
 *   distribution.  
 *
 * * Neither the name of the University of California, Berkeley nor
 *   the names of its contributors may be used to endorse or promote
 *   products derived from this software without specific prior 
 *   written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 */

package blog;

import java.util.*;
import common.Util;

public abstract class Formula extends ArgSpec {


    

    public boolean isTrue(PartialWorld w) {
	return ((Boolean) evaluate(w)).booleanValue();
    }

    

    public int compile(LinkedHashSet callStack) {
	callStack.add(this);
	int errors = 0;

	for (Iterator iter = getSubformulas().iterator(); iter.hasNext(); ) {
	    errors += ((Formula) iter.next()).compile(callStack);
	}

	for (Iterator iter = getTopLevelTerms().iterator(); iter.hasNext(); ) {
	    errors += ((Term) iter.next()).compile(callStack);
	}

	callStack.remove(this);
	return errors;
    }

    

    public Collection getSubExprs() {
	return getSubformulas();
    }

    

    public Formula getStandardForm() {
	return this;
    }

    

    public Formula getEquivToNegation() {
	if (equivToNegation == null) {
	    // Note that the following call happens even if we previously 
	    // called getEquivToNegationInternal on this object and it 
	    // returned null.  In this case the method call is unnecessary, 
	    // but should be very fast.  
	    equivToNegation = getEquivToNegationInternal();
	}
	return equivToNegation;
    }

    

    protected Formula getEquivToNegationInternal() {
	return null;
    }

    

    public List getSubformulas() {
	return Collections.EMPTY_LIST;
    }

    

    public List getTopLevelTerms() {
	return Collections.EMPTY_LIST;
    }

    

    public boolean containsRandomSymbol() {
	for (Iterator iter = getSubformulas().iterator(); iter.hasNext(); ) {
	    if (((Formula) iter.next()).containsRandomSymbol()) {
		return true;
	    }
	}

	for (Iterator iter = getTopLevelTerms().iterator(); iter.hasNext(); ) {
	    if (((Term) iter.next()).containsRandomSymbol()) {
		return true;
	    }
	}

	return false;
    }

    

    public boolean containsTerm(Term target) {
	for (Iterator iter = getSubformulas().iterator(); iter.hasNext(); ) {
	    if (((Formula) iter.next()).containsTerm(target)) {
		return true;
	    }
	}

	for (Iterator iter = getTopLevelTerms().iterator(); iter.hasNext(); ) {
	    if (((Term) iter.next()).containsTerm(target)) {
		return true;
	    }
	}

	return false;
    }

    

    public boolean containsAnyTerm(Collection terms) {
	for (Iterator iter = terms.iterator(); iter.hasNext(); ) {
	    if (containsTerm((Term) iter.next())) {
		return true;
	    }
	}
	return false;
    }

    

    public Set getGenFuncsApplied(Term subject) {
	Set genFuncs = new HashSet();
	
	for (Iterator iter = getSubformulas().iterator(); 
	     iter.hasNext(); ) {
	    Formula sub = (Formula) iter.next();
	    genFuncs.addAll(sub.getGenFuncsApplied(subject));
	}
	
	for (Iterator iter = getTopLevelTerms().iterator();
	     iter.hasNext(); ) {
	    Term t = (Term) iter.next();
	    genFuncs.addAll(t.getGenFuncsApplied(subject));
	}

	return Collections.unmodifiableSet(genFuncs);
    }

    

    public ConjFormula getPropCNF() {
	return new ConjFormula(new DisjFormula(this));
    }

    

    public DisjFormula getPropDNF() {
	return new DisjFormula(new ConjFormula(this));
    }

    

    public boolean isLiteral() {
	return false;
    }

    

    public boolean isQuantified() {
	return false;
    }

    

    public boolean isElementary() {
	for (Iterator iter = getSubformulas().iterator(); iter.hasNext(); ) {
	    Formula sub = (Formula) iter.next();
	    if (!(sub.isLiteral() || sub.isQuantified())) {
		return false;
	    }
	}
	return true;
    }

    

    public abstract Set getSatisfiersIfExplicit(EvalContext context, 
						LogicalVar subject, 
						GenericObject genericObj);

    

    public Set getNonSatisfiersIfExplicit(EvalContext context, 
					  LogicalVar subject,
					  GenericObject genericObj) {
	Formula neg = getEquivToNegation();
	if (neg == null) {
	    throw new UnsupportedOperationException
		("Can't get simplified equivalent to negation of " + this);
	}
	return neg.getSatisfiersIfExplicit(context, subject, genericObj);
    }

    

    public static final Set NOT_EXPLICIT
	= Collections.singleton("NOT_EXPLICIT");

    

    public static final Set ALL_OBJECTS 
	= Collections.singleton("ALL_OBJECTS");

    private Formula equivToNegation = null;
}

This file was generated on Tue Jun 08 17:53:36 PDT 2010 from file Formula.java
by the ilog.language.tools.Hilite Java tool written by Hassan Aït-Kaci