Accord.Math.Optimization.ExpressionParser.Parse C# (CSharp) Method

        public static void Parse(SortedSet<string> list, Expression expr)
        {
            if (expr == null)
                return;

            BinaryExpression eb = expr as BinaryExpression;
            MemberExpression em = expr as MemberExpression;
            UnaryExpression eu = expr as UnaryExpression;
            MethodCallExpression ec = expr as MethodCallExpression;


            if (em != null) // member expression
            {
                list.Add(em.Member.Name);
            }
            else if (eb != null) // binary expression
            {
                Parse(list, eb.Left);
                Parse(list, eb.Right);
            }
            else if (eu != null) // unary expression
            {
                Parse(list, eu.Operand);
            }
            else if (ec != null) // call expression
            {
                foreach (var a in ec.Arguments)
                    Parse(list, a);
            }


            return;
        }