Ruby Cookbook: review

I recently bought the Ruby Cookbook. I bought the italian version (whose title is 'Ruby Cookbook con elementi di Rails' which roughly translates to 'Ruby Cookbook with elements of Rails'). However, the book itself is not different.

Although I prefer to read technical books in English, I often buy books in Italian in order to show the publisher interest on that particular technology. In fact, in a country where most people avoid buying book in English because they feel they are 'too' difficult (like in Italy), good technologies do not spread if there are no good books in the local language.

The first impression with the book has been terribly negative. Actually if instead of buying the book online, I found it in a shop and leafed through it, I suppose I would have put it down.

Strings in Ruby are much like strings in other dynamic languages like Perl, Python

and PHP. They’re not too much different from strings in Java and C. Ruby strings are dynamic, mutable, and flexible.

In this paragraph you learn that "Ruby strings are dynamic, mutable, and flexible." And that is true. However, you get another impression: the authors do not know what they are talking about.

They say that Ruby strings are 'much like' the strings in Perl. This is almost true (well, Perl unicode support is much better than Ruby, and Perl deals natively with unicode strings. However, saying that Ruby strings are like Python strings is plainly wrong: Python strings are immutable and are somewhat more akin to Ruby symbols (in fact if you call intern on a Python string you get something semantically very similar to a Ruby symbol). Moreover, Python deals with unicode natively.

Again, the comparison with Java strings is plainly wrong: in Java strings are immutable. The comparison with C is terrible: in C, strings are not even a primitive data type.

As I said before, at this point I was tempted to put the book on a shelf and never open it again. Luckily enough I went on and soon enough I found out I bought one of the best books on Ruby available.

The impression that the authors are not competent (or at least they speak of something they do not know) is plainly wrong. A few chapters later, there are some chapters that quite accurately confront Ruby pragmatic with Python one. They are poignant and precise: definitely the authors know both languages quite well. I suppose the 'bad' paragraph at the beginning was a tentative to be didactical.

The book in fact is quite didactical. You can read it with almost no previous knowledge of Ruby. The reader is guided through Ruby syntactical conventions (for example when dealing with strings, you learn that parentheses are optional, which is known to everybody who coded a bit in Ruby).

In the later chapters (most notably the ones on modules and objects), the reader learns the nature of Ruby power, and how to reason and develop in order to unleash that power. This book is a cookbook, but every single receipt does more than teaching a way to achieve its goal: it teaches something about the way Ruby programmers should think and code *in general*. In fact you can consider this cookbook a 'beginner' book that teaches by examples (and that is a very effective way in a language such as Ruby). Of course, there is also plenty of intermediate and advanced stuff, or subjects not covered elsewhere (for example the ones about image manipulation).

This is a precious book and the ideal companion for everyone who's seriously motivated in learning Ruby. But it is also a book that a Ruby programmer may want to keep on her desk to find out how to do things without reinventing the wheel.