Bike.Interpreter.Interpreter.Walk C# (CSharp) Метод

        public override object Walk(UnaryExpression node)
        {
            var value = node.Expression.Accept(this);
            if (node.Postfix != TokenType.None)
            {
                switch (node.Postfix)
                {
                    case TokenType.DoublePlus:
                        {
                            var id = node.Expression.As<Identifier>("Identifier").Value;
                            Context.CurrentFrame.Assign(id, OpDoublePlus(value));
                            break;
                        }
                    case TokenType.DoubleMinus:
                        {
                            var id = node.Expression.As<Identifier>("Identifier").Value;
                            Context.CurrentFrame.Assign(id, OpDoubleMinus(value));
                            break;
                        }
                    default:
                        throw ErrorFactory.CreateInvalidProgramError("Invalid unary postfix");
                }
            }
            if (node.Prefix != TokenType.None)
            {
                switch(node.Prefix)
                {
                    case TokenType.DoublePlus:
                        {
                            var id = node.Expression.As<Identifier>("Identifier").Value;
                            value = OpDoublePlus(value);
                            Context.CurrentFrame.Assign(id, value);
                            break;
                        }
                    case TokenType.DoubleMinus:
                        {
                            var id = node.Expression.As<Identifier>("Identifier").Value;
                            value = OpDoubleMinus(value);
                            Context.CurrentFrame.Assign(id, value);
                            break;
                        }
                    case TokenType.Plus:
                        value = OpPlus(value);
                        break;
                    case TokenType.Minus:
                        value = OpMinus(value);
                        break;
                    case TokenType.Not:
                        value = OpNot(value);
                        break;
                    default:
                        throw ErrorFactory.CreateInvalidProgramError("Invalid unary prefix");
                }
            }
            return value;
        }