kodkod.ast.BinaryExpression Java Examples

/**
 * Calls lookup(binExpr) and returns the cached value, if any.  
 * If a translation has not been cached, translates the expression,
 * calls cache(...) on it and returns it.
 * @return let t = lookup(binExpr) | some t => t, 
 *      let op = (binExpr.op).(UNION->or + INTERSECTION->and + DIFFERENCE->difference + OVERRIDE->override + JOIN->dot + PRODUCT->cross) | 
 *       cache(binExpr, op(binExpr.left.accept(this), binExpr.right.accept(this)))
 */
public BooleanMatrix visit(BinaryExpression binExpr) {
	BooleanMatrix ret = lookup(binExpr);
	if (ret!=null) return ret;

	final BooleanMatrix left = binExpr.left().accept(this);
	final BooleanMatrix right = binExpr.right().accept(this);
	final ExprOperator op = binExpr.op();

	switch(op) {
	case UNION        	: ret = left.or(right); break;
	case INTERSECTION	: ret = left.and(right); break;
	case DIFFERENCE 	: ret = left.difference(right); break;
	case OVERRIDE 		: ret = left.override(right); break;
	case JOIN 			: ret = left.dot(right); break;
	case PRODUCT		: ret = left.cross(right); break;
	default : 
		throw new IllegalArgumentException("Unknown operator: " + op);
	}

	return cache(binExpr, ret);
}
 

/** @return true if e is (a product of) Expression.NONE*/
private boolean isEmpty(Expression e) { 
	if (e==Expression.NONE) return true;
	else if (e instanceof BinaryExpression) { 
		final BinaryExpression b = (BinaryExpression) e;
		return b.op()==ExprOperator.PRODUCT && isEmpty(b.left()) && isEmpty(b.right());
	} else if (e instanceof NaryExpression) { 
		final NaryExpression n = (NaryExpression) e;
		if (n.op()==ExprOperator.PRODUCT) { 
			for(int i = 0, max = n.size(); i < max; i++) { 
				if (!isEmpty(n.child(i))) return false;
			}
			return true;
		}
	}
	return false;
}
 

/** @effects appends the tokenization of the given node to this.tokens */
public void visit(BinaryExpression node) {
	if (displayed(node)) return;
	final boolean oldTop = notTop();
	final ExprOperator op = node.op();
	final Expression left = node.left(), right = node.right();
	if (op==ExprOperator.JOIN && left.arity()==1 && right.arity()==2 && right instanceof Relation) { 
		append(right);
		append("[");
		visitChild(left, false);
		append("]");
	} else {
		visitChild(left, parenthesize(op, left));
		infix(op);
		visitChild(right, parenthesize(op, right));
	}
	top = oldTop;
}
 

public Expression visit(BinaryExpression expr) { 
	Expression ret = lookup(expr);
	if (ret!=null) return ret;
	final ExprOperator op = expr.op();
	final Expression left = expr.left().accept(this);
	final Expression right = expr.right().accept(this);
	
	ret = simplify(op, left, right);
	
	if (ret==null) {
		ret = left==expr.left()&&right==expr.right() ? expr : left.compose(op, right);
	}
	
	return cache(expr,ret);
}
 

/** @ensures appends the tokenization of the given node to this.tokens */
public void visit(BinaryExpression node) {
	final ExprOperator op = node.op();
	visitChild(node.left(), parenthesize(op, node.left()));
	infix(op);
	visitChild(node.right(), parenthesize(op, node.right()));
}
 

/** @return true if the given  expression needs to be parenthesized if a 
 * child of a binary  expression with the given operator */
private boolean parenthesize(ExprOperator op, Expression child) { 
	return child instanceof IfExpression ||
		   child instanceof NaryExpression ||
	       (child instanceof BinaryExpression && 
	        (op==ExprOperator.JOIN || 
	         ((BinaryExpression)child).op()!=op));
}
 

/** 
 * Calls lookup(binExpr) and returns the cached value, if any.  
 * If no cached value exists, visits each child, caches the
 * union of the children's return values and returns it. 
 * @return let x = lookup(binExpr) | 
 *          x != null => x,  
 *          cache(binExpr, binExpr.left.accept(this) + binExpr.right.accept(this)) 
 */
public Set<T> visit(BinaryExpression binExpr) {
	Set<T> ret = lookup(binExpr);
	if (ret!=null) return ret;		
	ret = newSet();
	ret.addAll(binExpr.left().accept(this));
	ret.addAll(binExpr.right().accept(this));
	return cache(binExpr, ret);
}
 

public Expression visit(BinaryExpression expr) { 
	Expression ret = lookup(expr);
	if (ret!=null) return ret;
	final ExprOperator op = expr.op();
	final Expression left = expr.left().accept(this);
	final Expression right = expr.right().accept(this);
	
	ret = simplify(op, left, right);
	
	if (ret==null) {
	
		final int hash = hash(op, left, right);
		for(Iterator<PartialCannonicalizer.Holder<Expression>> itr = exprs.get(hash); itr.hasNext(); ) {
			final Expression next = itr.next().obj;
			if (next instanceof BinaryExpression) { 
				final BinaryExpression hit = (BinaryExpression) next;
				if (hit.op()==op && hit.left()==left && hit.right()==right) { 
					return cache(expr, hit);
				}
			}
		}

		ret = left==expr.left()&&right==expr.right() ? expr : left.compose(op, right);
		exprs.add(new PartialCannonicalizer.Holder<Expression>(ret, hash));
	}
	
	return cache(expr,ret);
}
 

/** 
 * Calls lookup(binExpr) and returns the cached value, if any.  
 * If a replacement has not been cached, visits the expression's 
 * children.  If nothing changes, the argument is cached and
 * returned, otherwise a replacement expression is cached and returned.
 * @return { b: BinaryExpression | b.left = binExpr.left.accept(this) &&
 *                                 b.right = binExpr.right.accept(this) && b.op = binExpr.op }
 */
public Expression visit(BinaryExpression binExpr) {
	Expression ret = lookup(binExpr);
	if (ret!=null) return ret;
	
	final Expression left  = binExpr.left().accept(this);
	final Expression right = binExpr.right().accept(this);
	ret = (left==binExpr.left() && right==binExpr.right()) ?
		  binExpr : left.compose(binExpr.op(), right);
	return cache(binExpr,ret);
}
 

/**
 * If x = SOMETHING->RELATION where SOMETHING.arity==1, then return the
 * RELATION, else return null.
 */
private static Relation right(Expression x) {
    if (!(x instanceof BinaryExpression))
        return null;
    BinaryExpression bin = (BinaryExpression) x;
    if (bin.op() != ExprOperator.PRODUCT)
        return null;
    if (bin.left().arity() == 1 && bin.right() instanceof Relation)
        return (Relation) (bin.right());
    else
        return null;
}
 

/** {@inheritDoc} */
@Override
public void visit(BinaryExpression x) {
    String newname = makename(x);
    if (newname == null)
        return;
    String left = make(x.left());
    String right = make(x.right());
    switch (x.op()) {
        case DIFFERENCE :
            file.printf("Expression %s=%s.difference(%s);%n", newname, left, right);
            break;
        case INTERSECTION :
            file.printf("Expression %s=%s.intersection(%s);%n", newname, left, right);
            break;
        case JOIN :
            file.printf("Expression %s=%s.join(%s);%n", newname, left, right);
            break;
        case OVERRIDE :
            file.printf("Expression %s=%s.override(%s);%n", newname, left, right);
            break;
        case PRODUCT :
            file.printf("Expression %s=%s.product(%s);%n", newname, left, right);
            break;
        case UNION :
            file.printf("Expression %s=%s.union(%s);%n", newname, left, right);
            break;
        default :
            throw new RuntimeException("Unknown kodkod operator \"" + x.op() + "\" encountered");
    }
}
 

/**
 * @ensures appends the tokenization of the given node to this.tokens
 */
@Override
public void visit(BinaryExpression node) {
    final ExprOperator op = node.op();
    visitChild(node.left(), parenthesize(op, node.left()));
    infix(op);
    visitChild(node.right(), parenthesize(op, node.right()));
}
 

/** @return true if the given  expression needs to be parenthesized if a 
 * child of a binary  expression with the given operator */
private boolean parenthesize(ExprOperator op, Expression child) { 
	return display.containsKey(child.toString()) ? false :
		   child instanceof IfExpression ||
		   (child instanceof NaryExpression && ((NaryExpression)child).op()!=op) ||
	       (child instanceof BinaryExpression && 
	        (/*op!=ExprOperator.JOIN && */
	         ((BinaryExpression)child).op()!=op));
}
 

/**
 * Calls lookup(binExpr) and returns the cached value, if any. If a translation
 * has not been cached, translates the expression, calls cache(...) on it and
 * returns it.
 *
 * @return let t = lookup(binExpr) | some t => t, let op =
 *         (binExpr.op).(UNION->or + INTERSECTION->and + DIFFERENCE->difference
 *         + OVERRIDE->override + JOIN->dot + PRODUCT->cross) | cache(binExpr,
 *         op(binExpr.left.accept(this), binExpr.right.accept(this)))
 */
@Override
public BooleanMatrix visit(BinaryExpression binExpr) {
    BooleanMatrix ret = lookup(binExpr);
    if (ret != null)
        return ret;

    final BooleanMatrix left = binExpr.left().accept(this);
    final BooleanMatrix right = binExpr.right().accept(this);
    final ExprOperator op = binExpr.op();

    switch (op) {
        case UNION :
            ret = left.or(right);
            break;
        case INTERSECTION :
            ret = left.and(right);
            break;
        case DIFFERENCE :
            ret = left.difference(right);
            break;
        case OVERRIDE :
            ret = left.override(right);
            break;
        case JOIN :
            ret = left.dot(right);
            break;
        case PRODUCT :
            ret = left.cross(right);
            break;
        default :
            throw new IllegalArgumentException("Unknown operator: " + op);
    }

    return cache(binExpr, ret);
}
 

/**
 * Calls lookup(binExpr) and returns the cached value, if any. If no cached
 * value exists, visits each child, caches the union of the children's return
 * values and returns it.
 *
 * @return let x = lookup(binExpr) | x != null => x, cache(binExpr,
 *         binExpr.left.accept(this) + binExpr.right.accept(this))
 */
@Override
public Set<T> visit(BinaryExpression binExpr) {
    Set<T> ret = lookup(binExpr);
    if (ret != null)
        return ret;
    ret = newSet();
    ret.addAll(binExpr.left().accept(this));
    ret.addAll(binExpr.right().accept(this));
    return cache(binExpr, ret);
}
 

/**
 * Visits the left and right subexpressions if this.visited(binExpr) returns
 * false. Otherwise does nothing.
 *
 * @ensures binExpr.left.accept(this) && binExpr.right.accept(this)
 */
@Override
public void visit(BinaryExpression binExpr) {
    if (visited(binExpr))
        return;
    binExpr.left().accept(this);
    binExpr.right().accept(this);
}
 

/**
 * Calls lookup(binExpr) and returns the cached value, if any. If a replacement
 * has not been cached, visits the expression's children. If nothing changes,
 * the argument is cached and returned, otherwise a replacement expression is
 * cached and returned.
 *
 * @return { b: BinaryExpression | b.left = binExpr.left.accept(delegate) &&
 *         b.right = binExpr.right.accept(delegate) && b.op = binExpr.op }
 */
@Override
public Expression visit(BinaryExpression binExpr) {
    Expression ret = lookup(binExpr);
    if (ret != null)
        return ret;

    final Expression left = binExpr.left().accept(delegate);
    final Expression right = binExpr.right().accept(delegate);
    ret = (left == binExpr.left() && right == binExpr.right()) ? binExpr : left.compose(binExpr.op(), right);
    return cache(binExpr, ret);
}
 

@Override
public void visit(BinaryExpression binExpr) {
    visit(binExpr, binExpr.op(), binExpr.left(), binExpr.right());
}
 

@Override
public Boolean visit(BinaryExpression expr) {
    return checkVisitedThenAccumA(expr, Boolean.FALSE, expr.left(), expr.right());
}
 

/** @return true if the given expression should be parenthesized when a 
 * child of a compound parent */
private boolean parenthesize(Expression child) { 
	return (display.isEmpty() || !display.containsKey(child.toString())) &&
	       (child instanceof BinaryExpression || child instanceof NaryExpression || child instanceof IfExpression); 
}
 

@Override
public E visit(BinaryExpression binExpr) {
    start(binExpr);
    return end(binExpr, visitor.visit(binExpr));
}
 

@Override
public Expression visit(BinaryExpression binExpr) {
    return binExpr;
}
 

/**
 * Visits the left and right subexpressions  if
 * this.visited(binExpr) returns false.  Otherwise does nothing.
 * @ensures binExpr.left.accept(this) && binExpr.right.accept(this)
 */
public void visit(BinaryExpression binExpr) {
	if (visited(binExpr)) return;
	binExpr.left().accept(this);
	binExpr.right().accept(this);
}
 

public void visit(BinaryExpression binExpr) { 
	visit(binExpr, binExpr.op(), binExpr.left(), binExpr.right()); 
}
 

/** @return true if the given expression should be parenthesized when a 
 * child of a compound parent */
private boolean parenthesize(Expression child) { 
	return child instanceof BinaryExpression || child instanceof IfExpression; 
}
 

/** 
* Visits the given binary expression. 
**/
  public void visit(BinaryExpression binExpr);
 

/** 
 * Calls lookup(binExpr) and returns the cached value, if any.  
 * If no cached value exists, visits each child, caches the
 * disjunction of the children's return values and returns it. 
 * @return let x = lookup(binExpr) | 
 *          x != null => x,  
 *          cache(binExpr, binExpr.left.accept(this) || binExpr.right.accept(this)) 
 */
public Boolean visit(BinaryExpression binExpr) {
	final Boolean ret = lookup(binExpr);
	return (ret!=null) ? ret : cache(binExpr, binExpr.left().accept(this) || binExpr.right().accept(this));
}
 

/** 
* Visits the given binary expression and returns the result.
* @return the result of visiting <code>binExpr</code> 
**/
  public E visit(BinaryExpression binExpr);
 

/**
 * @return true if the given expression needs to be parenthesized if a child of
 *         a binary expression with the given operator
 */
private boolean parenthesize(ExprOperator op, Expression child) {
    return child instanceof IfExpression || child instanceof NaryExpression || (child instanceof BinaryExpression && (op == ExprOperator.JOIN || ((BinaryExpression) child).op() != op));
}
 

/**
 * @return true if the given expression should be parenthesized when a child of
 *         a compound parent
 */
private boolean parenthesize(Expression child) {
    return child instanceof BinaryExpression || child instanceof IfExpression;
}