public void Interpret(ContextEx context) { if (context.Input.Length == 0) { return; } if (context.Input.StartsWith(Nine())) { context.Output += (9 * Multiplier()); context.Input = context.Input.Substring(2); } else if (context.Input.StartsWith(Four())) { context.Output += (4 * Multiplier()); context.Input = context.Input.Substring(2); } else if (context.Input.StartsWith(Five())) { context.Output += (5 * Multiplier()); context.Input = context.Input.Substring(1); } while (context.Input.StartsWith(One())) { context.Output += (1 * Multiplier()); context.Input = context.Input.Substring(1); } }
/// <summary> /// Entry point into console application. /// </summary> public void Execute() { string roman = "MCMXXVIII"; ContextEx context = new ContextEx(roman); // Build the 'parse tree' List <Expression> tree = new List <Expression>(); tree.Add(new ThousandExpression()); tree.Add(new HundredExpression()); tree.Add(new TenExpression()); tree.Add(new OneExpression()); // Interpret foreach (Expression exp in tree) { exp.Interpret(context); } Console.WriteLine("{0} = {1}", roman, context.Output); }