Advanced Ruby Features.

In this chapter we're going to look at some advanced Ruby techniques that have not been covered in prior chapters. This chapter is the last instructional chapter in the second part of the book, and although we'll be covering useful libraries, frameworks, and Ruby-related technologies in Part 3, this chapter rounds off the mandatory knowledge that any proficient Ruby programmer should have. This means that although this chapter will jump between several different topics, each is essential to becoming a professional Ruby developer. [ABSTRACT FROM AUTHOR]