process lotto。txt and get a correctly formatted data stream。 Piping Binary Data When working with the console； for the most part； you will be transferring text data from one process to another or from one file to another file。 However； when developing in ； working …………………………………………………………Page 291…………………………………………………………… CH A PT E R 1 0 ■ L E A R N I N G A B O U T P E R S IS T E N CE 269 with text is not always the best choice。 A more efficient approach might be to store the data in a binary format。 The easiest way to understand the difference between text data and binary data is to open a binary file using a text editor； as shown in Figure 10…8。 Figure 10…8。 A binary file in a text editor In Figure 10…8； you see just a bunch of funny characters with some text scattered throughout。 A binary file is different from a text file in that the format of a binary file is whatever the program that reads and writes the binary data decides。 The advantage of using a binary file is that you can create plex structures。 The disadvantage is that only the developer of the reader/writer program knows what the file contains。 Binary files are not always smaller； but they are more efficient because you do not need to parse and process the data。 For example； in the text…based lottery data stream reader； we needed to parse every single line and then split the line of text into individual fields； which were then parsed as integers and assigned to a variable。 Using a binary file； you only need to create a binary type； and read or write that type。 In this section； we will continue with the example of the lottery…prediction application； but this time； create it as a console application that converts a text data stream into a binary data stream and then back to a text stream。 You’ll see how you can pipe the data from one stream to another by sending it from one application to another application。 When we are finished building this application； the following mand line will be valid。 type lotto。txt ｜ TextProcessor。exe ｜ Text2Binary。exe ｜ Binary2Text。exe The mand line starts with generating a text data stream using the type mand。 The mand TextProcessor。exe generates a clean data stream that is then piped into …………………………………………………………Page 292…………………………………………………………… 270 CH AP T E R 1 0 ■ L E A R N I N G A B OU T P E R S IS TE N CE Text2Binary。exe； which generates a binary data stream。 Finally； the binary data stream is converted back into a text stream using Binary2Text。exe； which displays the data on the console。 The architecture of TextProcessor with its implementation of the IProcessor interface and a general architecture of grabbing a file or console input/output stream worked。 However； IProcessor is not usable for binary streams； so we need to implement a new interface and architecture。 ■Note The examples that follow illustrate a very mon situation where an architecture worked and the ideas of the architecture could be applied in the new context。 What does not work is the actual implementa tion of the original architecture。 You may be tempted to modify the working architecture so that it will work with the new context。 As much as you would like to do that； don’t。 Often； the abstractions you create will plicate the architecture and make the resulting code more plex。 Your challenge is to know when to generalize an architecture and when to keep the ideas of an architecture but create a new implementation； and you’ll learn this with experience。 Defining the Interfaces and Implementing the Shell In ； the data streams are split into two types of streams： binary and text。 The TextWriter and TextReader types are used to read text…based data streams。 As was demonstrated with the StringReader type； when dealing with text…based streams； certain assumptions can be made； such as being able to find new lines in the stream。 With binary data streams； no such assump tions can be made。 Binary streams have their own format； which is known by only the program doing the reading or writing。 The binary stream…based types can be used to process text data streams； but doing so would require knowing the details of the data stream。 Remember that gives you a text…handling system that understands the different Unicode code pages。 A Unicode code page is a specific translation map。 If you decide to manipulate the text streams using binary stream types； you are telling that you will manage the details of the Unicode code pages。 Of course； you don’t want to do that； and thus should never mix data streams。 So； for our sample application； we need to design two different interfaces： one to stream from text to binary and one to stream from binary to text。 ■Note For more information about Unicode and other text…related issues； see the MSDN “International Text Display” section （http：//msdn2。microsoft。/en…us/library/ms776131。aspx）。 The following is the binary…to…text data stream interface； Binary2Text。IBinary2TextProcessor。 Imports System。IO Public Interface IBinary2TextProcessor Sub Process（ByVal input As Stream； ByVal output As TextWriter） End Interface …………………………………………………………Page 293…………………………………………………………… CH A PT E R 1 0 ■ L E A R N I N G A B O U T P E R S IS T E N CE 271 The IBinary2TextPr