Audience

Audience
	Preface

Our primary audience is programmers who are new to OO programming. Have you found your first exposure to objects to be more distasteful than empowering? Why does this happen? Some instructors launch into extensive presentations on object orientation before getting to the language fundamentals, leaving students lost as to how they will accomplish the noble and lofty goals of OO. Other instructors leave OO for last, exposing the procedural side of the language first, and treating objects as a kind of add-on. This leaves students feeling that objects are optional. Additionally, some very skilled instructors are not skilled developers, and will often show examples that don't reflect currently accepted best practices.

Our audience has an exposure to the language, but needs more time to understand objects and object-orientation. We want to provide exercises that have four key features: just complex enough to require careful design work, just fun enough to be engaging, easy enough that results are available immediately, and can be built in simple stages.

In our effort to support the beginning student, we'll provide a few additional details on language features. We'll mark these as “Tips” for the new programmer, and qualify the tip by language. For more advanced students, these tips will be review material. We will not provide a thorough background in any programming language. The student is expected to know the basics of the language and tools.

Helpful additional skills include using one of the various unit test and documentation frameworks available. We've included information in the appendices.

Instructors are always looking for classroom projects that are engaging, comprehensible, and focus on perfecting language skills. Many real-world applications require considerable explanation of the problem domain; the time spent reviewing background information detracts from the time available to do the relevant programming. While all application programming requires some domain knowledge, the idea behind these exercises is to pick a domain that many people know a little bit about. This allows an instructor to use some or all of these exercises without wasting precious classroom time on incidental details required to understand the problem.

This book assumes an introductory level of skill in an OO programming language. We provide specific examples in Java (at least version 1.4) and Python (at least version 2.5). Student skills we expect include the following.

Create source files, compile and run application programs. While this may seem obvious, we don't discuss any integrated development environment (IDE). We have to assume these basic skills are present.
Use of the core procedural programming constructs: variables, statements, exceptions, functions. We will not, for example, spend any time on design of loops that terminate properly.
Some exposure to class definitions and subclasses. This includes managing the basic features of inheritance, as well as overloaded method names. We will avoid Python-unique features like multiple inheritance and callable objects, and focus on that subset of Python features that map directly to Java. For the Python equivalent of overloaded methods, we will assume that Python programmers can make use of default parameter values and named parameters.
Some exposure to the various collections frameworks. For Java programmers, this means the classes in the java.util package. For Python programmers, this means the built-in sequence and mapping types.
Optionally, some experience with a unit testing framework. See the appendices for supplemental exercises if you aren't familiar with Python's unittest or doctest or Java's JUnit.
Optionally, some experience writing formal documentation. For Java programmers, this means javadoc comments. For Python programmers, this often means Epydoc or a similar documentation package. See the appendices for supplemental exerises if you aren't familiar with formal, deliverable documentation.


Preface		Organization of This Book