# Has anyone read this book?

**URL:** <https://www.ruby-forum.com/t/has-anyone-read-this-book/135923>\
**Category:** Ruby\
**Created:** [April 26, 2008, 11:04am UTC](https://www.ruby-forum.com/t/has-anyone-read-this-book/135923 "2008-04-26T11:04:32Z")\
**Posts on this page:** 6\
**Page:** 1

<div class="post-metadata">

**Author:** ![Laurent\_J](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/67e7ee/32.png) [@Laurent\_J](https://www.ruby-forum.com/u/Laurent_J)\
**Post date:** [April 26, 2008, 11:04am UTC](https://www.ruby-forum.com/t/has-anyone-read-this-book/135923/1 "2008-04-26T11:04:32Z")

</div>

Yesterday I cam across a Web page mentioning this book on “Data  
Structures and Algorithms with Object-Oriented Design Patterns in Ruby”  
by Bruno R. Preiss.

[http://www.brpreiss.com/books/opus8/](http://www.brpreiss.com/books/opus8/)

I’d like to know if anyone has read this book with care and has an  
opinion about it? I spend an hour or so on it and was under the  
impression that the content was good but that the source code of the  
examples look a bit too Java-ish.

Note: The same book for JAVA and C++ was published on paper by Wiley.

Thanks for you comments.

Laurent

---

<div class="post-metadata">

**Author:** ![Laurent\_J](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/67e7ee/32.png) [@Laurent\_J](https://www.ruby-forum.com/u/Laurent_J)\
**Post date:** [April 26, 2008, 12:10pm UTC](https://www.ruby-forum.com/t/has-anyone-read-this-book/135923/2 "2008-04-26T12:10:53Z")

</div>

-----BEGIN PGP SIGNED MESSAGE-----  
Hash: SHA1

Laurent J. wrote:

> […] I’d like to know if anyone has read this book with care and has an  
> opinion about it? I spend an hour or so on it and was under the  
> impression that the content was good but that the source code of the  
> examples look a bit too Java-ish.

Hi Laurent,

versions of the book exist for C++, Java, C#, Python, Lua, Perl, PHP and  
Ruby. The focus is clearly on the algorithms and the code is just  
adapted for the given language. It’s not idiomatic Ruby.

While idiomatic C++, Java and C# are roughly similar, this is not the  
case when you also consider Ruby, Perl or Python.

For example, Program 2.6 is:

def geometricSeriesSum(x, n)  
sum = 0  
i = 0  
while i \<= n  
prod = 1  
j = 0  
while j \< i  
prod \*= x  
j += 1  
end  
sum += prod  
i += 1  
end  
return sum  
end

Which is, from a Ruby standpoint, a mess.

In Ruby, you’d most likely write something along the lines of:

def geometric\_sum(x, n)  
(0…n).inject(0) { |sum, i| sum + x\*\*i }  
end

or use Enumberable#sum directly.

Cheers,  
Antonio

* * *

[http://antoniocangiano.com](http://antoniocangiano.com) - Zen and the Art of Programming  
[http://stacktrace.it](http://stacktrace.it) - Aperiodico di resistenza informatica  
[http://math-blog.com](http://math-blog.com) - Math Blog: Mathematics is wonderful!  
-----BEGIN PGP SIGNATURE-----  
Version: GnuPG v1.4.8 (Darwin)  
Comment: Using GnuPG with Mozilla - [http://enigmail.mozdev.org](http://enigmail.mozdev.org)

iEYEARECAAYFAkgS/ooACgkQqCqsu0qUj9RW0wCdEMU/N19SlCzXu6NGtiajyXND  
DFUAoKHpNMC6C03oDClpYw9vq1pIYU/6  
=w3TF  
-----END PGP SIGNATURE-----

---

<div class="post-metadata">

**Author:** ![Laurent\_J](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/67e7ee/32.png) [@Laurent\_J](https://www.ruby-forum.com/u/Laurent_J)\
**Post date:** [April 26, 2008, 1:21pm UTC](https://www.ruby-forum.com/t/has-anyone-read-this-book/135923/3 "2008-04-26T13:21:13Z")

</div>

On Sat, 2008-04-26 at 18:03 +0900, Laurent J. wrote:

> Note: The same book for JAVA and C++ was published on paper by Wiley.

This is always a bad sign. Even between two languages as similar as  
Java and C++ having the same book in versions for each language means  
one of two things:

```
 1. The code involved is so trivial it is of little value.
 2. One (or both!) of the languages are getting short shrift in
    terms of proper, idiomatic use.

```

Given that Ruby is hugely different from Java and C++ I’m guessing  
without bothering to check that the book is a waste of the Ruby  
programmer’s time. I base this opinion on experiences with a line of  
books that purported to teach algorithms and data structures for Pascal,  
C and C++. The only one that got decent treatment of the three was  
Pascal (the original book, apparently). The remaining two got clumsy  
translations that worked against the languages’ core idioms.

---

<div class="post-metadata">

**Author:** ![Laurent\_J](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/67e7ee/32.png) [@Laurent\_J](https://www.ruby-forum.com/u/Laurent_J)\
**Post date:** [April 26, 2008, 3:12pm UTC](https://www.ruby-forum.com/t/has-anyone-read-this-book/135923/4 "2008-04-26T15:12:04Z")

</div>

Antonio,

Thanks for your feedback. I reviewed a couple of Ruby source files and  
the code was not as bad as the one you spotted. Obviously the entire  
code needs to be rewritten if one want to make a good Ruby book out of  
it.

I was however under the impression that this could be a good reference  
book for data structures and algorithm in Ruby now that more and more  
people (finally !) realize that behind Rails there is a really good  
programming called Ruby.

Apart from the escellent “Desing Patterns in Ruby” by Russ Olsen there  
is not much litterature on the subject.

Laurent

---

<div class="post-metadata">

**Author:** ![Laurent\_J](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/67e7ee/32.png) [@Laurent\_J](https://www.ruby-forum.com/u/Laurent_J)\
**Post date:** [April 26, 2008, 4:00pm UTC](https://www.ruby-forum.com/t/has-anyone-read-this-book/135923/5 "2008-04-26T16:00:55Z")

</div>

Laurent J. wrote:

> Note: The same book for JAVA and C++ was published on paper by Wiley.
> 
> Thanks for you comments.
> 
> Laurent

This comes up fairly often on the list. I can’t say I’ve read _any_  
version of it in depth, but there are better books available on similar  
subjects in just about any (programming) language you can name.

For object-oriented design patterns in Ruby, your best bet is Russ  
Olsen’s _Design Patterns in Ruby_. I don’t know if there’s a good book  
on data structures and algorithms in Ruby, though. Data structures and  
algorithms are often explored in a language-independent manner, and  
often using the “natural” recursive formulations. Translation to  
specific programming languages is left as “an exercise for the student.”  
🙂

---

<div class="post-metadata">

**Author:** ![Laurent\_J](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/l/67e7ee/32.png) [@Laurent\_J](https://www.ruby-forum.com/u/Laurent_J)\
**Post date:** [April 27, 2008, 4:54pm UTC](https://www.ruby-forum.com/t/has-anyone-read-this-book/135923/6 "2008-04-27T16:54:16Z")

</div>

If you’ve done C, you’ve come across the the most important data  
structures for it: structs, unions, enums, arrays, pointers, linked  
lists  
Well, really just knowing what of the standard types to use for what.

With Object Oriented programming (which can be done in C… just not  
gracefully) you get other things that are very useful and sometimes  
language dependent.  
In particular collection or container classes that include arrays and  
structs but take things to a new level of convenience.  
Hashes are commonly used with key-value pairs (some languages call  
them dictionaries or other names)

The most unique to ruby is the old Symbol class. Get the rest of Ruby  
and Symbol will make more sense, especially when and how it is useful.  
Ruby’s other unique feature is its ability to enumerate over its  
collection classes with great ease and power.

Beyond that, any data structures book will give you ideas.  
Take a look at other people’s code too.