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.IntOperator;
  import kodkod.ast.visitor.ReturnVisitor;
  import kodkod.ast.visitor.VoidVisitor;
  
  /**
   * A unary integer intExpr, e.g. -x.
   * @specfield intExpr: IntExpression
   * @specfield op: IntOperator
   * @invariant op.unary()
   * @invariant children = 0->intExpr
   * @author Emina Torlak
   */
  public final class UnaryIntExpression extends IntExpression {
  	private final IntOperator op;
  	private final IntExpression intExpr;
  	
  	/**
  	 * Constructs a new unary int formula: op intExpr
  	 * @ensures this.op' = op && this.intExpr' = intExpr
  	 */
  	UnaryIntExpression(IntOperator op, IntExpression intExpr) {
  		if (!op.unary()) throw new IllegalArgumentException("Not a unary operator: " + op);
  		this.op = op;
  		this.intExpr = intExpr;
  	}
  
  	/**
  	 * Returns the operator of this.
  	 * @return this.op
  	 */
  	public IntOperator op() {return op;}
  	
  	/**
  	 * Returns this.intExpr.
  	 * @return this.intExpr
  	 */
  	public IntExpression intExpr() {return intExpr;}
  	
  	/**
  	 * {@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==IntOperator.NEG||op==IntOperator.NOT) ? "(" + op + intExpr + ")" : op + "(" + intExpr + ")" ;
  	}
  }
  