A Ruby Book (free to use)

ruby-talk
1

Hello people, I have written a book on Ruby programming language.
Download it from here http://is.gd/r2012

···

--
Posted via http://www.ruby-forum.com/.

2

Hello people, I have written a book on Ruby programming language.
Download it from here is.gd - Shortened URL

Hello,

Thanks for the effort and for supplying an entire book for free. Is it possible to have .mobi and/or .epub versions?

Best Regards,

--
Posted via http://www.ruby-forum.com/\.

Panagiotis Atmatzidis

···

On 22 Αυγ 2012, at 09:10 , Karthikeyan A k <lists@ruby-forum.com> wrote:
-----------------------------
Pharmacy Student at VFU

email4lists: ml@convalesco.org
More info: http://about.me/atmosx

The wise man said: "Never argue with an idiot, he brings you down to his level and beat you with experience."

3

Thanks for sharing your work and esp. for the lovely "Math Discovery" at p. 162

regards
ralf

···

On 08/22/2012 08:10 AM, Karthikeyan A k wrote:

Hello people, I have written a book on Ruby programming language.
Download it from here is.gd - Shortened URL

4

Thanks so much! I haven't had time to look at most of it, but I notice
there are missing hyphens in some code sections, e.g. all of these on
p. 10:

$ sudo apt­get install build­essential bison openssl libreadline6 libreadline6­
dev curl git­core zlib1g zlib1g­dev libssl­dev libyaml­dev libsqlite3­0
libsqlite3­dev sqlite3 libxml2­dev libxslt­dev autoconf libc6­dev ncurses­dev
automake

and:

$ curl ­L https://get.rvm.io | bash ­s stable ­­ruby

and:

$ echo '[[ ­s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load
RVM function' >> ~/.bashrc

and:

$ ruby ­v

···

On Wed, Aug 22, 2012 at 1:10 AM, Karthikeyan A k <lists@ruby-forum.com> wrote:

Hello people, I have written a book on Ruby programming language.
Download it from here is.gd - Shortened URL

5

Though appreciating the effort that was put into this,
I would not recommend this at the moment as a good starting
point for beginners. There is still a lot of work to be done.

I only browsed a couple of pages and I found:

- a wrong algorithm (on p. 32)

   # finds the greatest of three numbers
   a,b,c = 3,7,5
   if a > b and a > c
   puts "a = #{a} is greatest"
   elsif b > c and b > a
   puts "b = #{b} is greatest"
   else puts "c = #{c} is greatest"
   end

   Now try that with a,b,c = 4,4,3 !
   => c = 3 is greatest

- doubtful simplifications and half-truths:

   "The p is a kind of short form for puts." (p. 33)

   "Note that if we use else with unless we must terminate
   the unless block with an end command." (p. 34)

- antipatterns (unless...else) (on p. 34):

   unless age < 18 or age > 35
       p "You can enter Armed forces"
       else p "You cannot enter Army. You are either too young or too old"
   end

   This highly confusing usage of unless finds its counterpart in
   sentences like "Let say that one is not a major and is considered
   a child unless he or she is less than 18 years old."
   (Which is wrong, by the way.)

- a programming style (indentations, ...) that does not follow the
   highly reasonable style widely established in the Ruby community
   (see above examples)

···

Am 22.08.2012 08:10, schrieb Karthikeyan A k:

Hello people, I have written a book on Ruby programming language.
Download it from here is.gd - Shortened URL

--
<https://github.com/stomar/&gt;

6

It is well known for a long time that you can prove anything if you
manage to sneak a division by zero into your proof. Various fun
proofs have been built around this. Note also that this has nothing
to do with how computers do math.

Kind regards

robert

···

On Wed, Aug 22, 2012 at 9:38 AM, Ralf Mueller <ralf.mueller@zmaw.de> wrote:

On 08/22/2012 08:10 AM, Karthikeyan A k wrote:

Hello people, I have written a book on Ruby programming language.
Download it from here is.gd - Shortened URL

Thanks for sharing your work and esp. for the lovely "Math Discovery" at p.
162

--
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

7

Thanks for this book !

···

On 22/08/2012 17:26, Eric Christopherson wrote:

On Wed, Aug 22, 2012 at 1:10 AM, Karthikeyan A k <lists@ruby-forum.com> wrote:

Hello people, I have written a book on Ruby programming language.
Download it from here is.gd - Shortened URL

Thanks so much! I haven't had time to look at most of it, but I notice
there are missing hyphens in some code sections, e.g. all of these on
p. 10:

$ sudo apt­get install build­essential bison openssl libreadline6 libreadline6­
dev curl git­core zlib1g zlib1g­dev libssl­dev libyaml­dev libsqlite3­0
libsqlite3­dev sqlite3 libxml2­dev libxslt­dev autoconf libc6­dev ncurses­dev
automake

and:

$ curl ­L https://get.rvm.io | bash ­s stable ­­ruby

and:

$ echo '[[ ­s "$HOME/.rvm/scripts/rvm" ]] && . "$HOME/.rvm/scripts/rvm" # Load
RVM function' >> ~/.bashrc

and:

$ ruby ­v

8

To avoid this problem, use this file
https://raw.github.com/mindaslab/ilrx/master/ruby_install.bash

Eric Christopherson wrote in post #1073242:

···

On Wed, Aug 22, 2012 at 1:10 AM, Karthikeyan A k <lists@ruby-forum.com> > wrote:

Hello people, I have written a book on Ruby programming language.
Download it from here is.gd - Shortened URL

Thanks so much! I haven't had time to look at most of it, but I notice
there are missing hyphens in some code sections, e.g. all of these on
p. 10:

$ sudo apt­get install build­essential bison openssl libreadline6
libreadline6­
.....s/rvm" ]] && . "$HOME/.rvm/scripts/rvm"
# Load
RVM function' >> ~/.bashrc

and:

$ ruby ­v

--
Posted via http://www.ruby-forum.com/\.

9

OK, fixed the bug on page 32, but others.... I think that's OK. Thanks,
spot more.

unknown wrote in post #1073171:

Hello people, I have written a book on Ruby programming language.
Download it from here is.gd - Shortened URL

Though appreciating the effort that was put into this,
........

I only browsed a couple of pages and I found:

- a wrong algorithm (on p. 32)

   # finds the greatest of three numbers
   a,b,c = 3,7,5
   .....
   else puts "c = #{c} is greatest"
   end

   Now try that with a,b,c = 4,4,3 !
   => c = 3 is greatest

......

···

Am 22.08.2012 08:10, schrieb Karthikeyan A k:
   end

   ......

--
Posted via http://www.ruby-forum.com/\.

10

Sure, it hasn't. You can proof everything out of something wrong, e.g. my math teacher proofed that he is the pope out of 1 = 2

···

On 08/22/2012 10:19 AM, Robert Klemme wrote:

On Wed, Aug 22, 2012 at 9:38 AM, Ralf Mueller <ralf.mueller@zmaw.de> wrote:

On 08/22/2012 08:10 AM, Karthikeyan A k wrote:

Hello people, I have written a book on Ruby programming language.
Download it from here http://is.gd/r2012

Thanks for sharing your work and esp. for the lovely "Math Discovery" at p.
162

It is well known for a long time that you can prove anything if you
manage to sneak a division by zero into your proof. Various fun
proofs have been built around this. Note also that this has nothing
to do with how computers do math.