From: Laurent Julliard <laurent@...>
Date: 2008-04-26T22:11:21+09:00
Subject: Re: Has anyone read this book?

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

Antonio Cangiano wrote:
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> Laurent Julliard 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 - Zen and the Art of Programming
> http://stacktrace.it - Aperiodico di resistenza informatica
> http://math-blog.com - Math Blog: Mathematics is wonderful!
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