April 2005
Beginner to intermediate
528 pages
16h 20m
English
Content preview from Practical Common Lisp
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CHAPTER 27Practical: An MP3 Database
In this chapter you'll revisit the idea first explored in Chapter 3 of building an in-memory database out of basic Lisp data structures. This time your goal is to hold information that you'll extract from a collection of MP3 files using the ID3v2 library from Chapter 25. You'll then use this database in Chapters 28 and 29 as part of a Web-based streaming MP3 server. Of course, this time around you can use some of the language features you've learned since Chapter 3 to build a more sophisticated version.
The Database
The main problem with the database in Chapter 3 is that there's only one table, the list stored in the variable *db*. Another is that the code doesn't know anything about what type of values are ...