From: Antonio Cangiano <acangiano@...>
Date: 2008-04-26T19:10:02+09:00
Subject: Re: Has anyone read this book?

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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
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