NotEqual.java

package calculator.interpreter.ast.logic;

import calculator.interpreter.Environment;
import calculator.interpreter.ast.InfixOp;

/**
 * Not equal operator
 */
public class NotEqual extends InfixOp {

  @Override
  public Object eval(Environment env) {
    Object a = first.eval(env);
    Object b = second.eval(env);
    return a == null ? b != null : !a.equals(b);
  }

}