content: /* 
   * Kodkod -- Copyright (c) 2005-present, Emina Torlak
   *
   * Permission is hereby granted, free of charge, to any person obtaining a copy
   * of this software and associated documentation files (the "Software"), to deal
   * in the Software without restriction, including without limitation the rights
   * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   * copies of the Software, and to permit persons to whom the Software is
   * furnished to do so, subject to the following conditions:
   *
   * The above copyright notice and this permission notice shall be included in
   * all copies or substantial portions of the Software.
   *
   * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
   * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
   * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
   * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
   * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
   * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
   * THE SOFTWARE.
   */
  package kodkod.ast;
  
  
  import kodkod.ast.operator.ExprCastOperator;
  import kodkod.ast.visitor.ReturnVisitor;
  import kodkod.ast.visitor.VoidVisitor;
  
  /**
   * An {@link kodkod.ast.IntExpression } representing the 
   * cardinality of an {@link kodkod.ast.Expression} or the 
   * sum of all the integer atoms contained in the expression.
   * @specfield expression: Expression
   * @specfield op: ExprCastOperator
   * @invariant children = 0->expression
   * @author Emina Torlak
   */
  public final class ExprToIntCast extends IntExpression {
  	private final Expression expression;
  	private final ExprCastOperator op; 
  	/**  
  	 * Constructs a new cardinality expression.
  	 * 
  	 * @ensures this.expression' = expression && this.op' = op
  	 * @throws NullPointerException  expression = null || op = null
  	 * @throws IllegalArgumentException  op = SUM && child.arity != 1
  	 */
  	ExprToIntCast(Expression child, ExprCastOperator op) {
  		if (child.arity()>1 && op==ExprCastOperator.SUM) 
  			throw new IllegalArgumentException("cannot apply " + op + " to " + child);
  		this.expression = child;
  		this.op = op;
  	}
  	
  	/**
  	 * Returns this.expression.
  	 * @return this.expression
  	 */
  	public Expression expression() {return expression;}
  
  	/**
  	 * Returns this.op.
  	 * @return this.op
  	 */
  	public ExprCastOperator op() { return op; } 
  	
  		
  	/**
  	 * {@inheritDoc}
  	 * @see kodkod.ast.IntExpression#accept(kodkod.ast.visitor.ReturnVisitor)
  	 */
  	@Override
  	public <E, F, D, I> I accept(ReturnVisitor<E, F, D, I> visitor) {
  		return visitor.visit(this);
  	}
  
  	/**
  	 * {@inheritDoc}
  	 * @see kodkod.ast.IntExpression#accept(kodkod.ast.visitor.VoidVisitor)
  	 */
  	@Override
  	public void accept(VoidVisitor visitor) {
  		visitor.visit(this);
  	}
  	
  	/**
  	 * {@inheritDoc}
  	 * @see kodkod.ast.Node#toString()
  	 */
  	public String toString() {
  		return op + "("+expression.toString()+")";
  	}
  	
  }
  