Ievgenii Narovlianskyi is a Software Developer in SeniorDevOnly AS, who has lot of experience developing large and small web systems of different kinds using Ruby language. Ruby is an awesome choice for those who are looking for fast development of rather complex systems. In this lecture Ievgenii showed the audience some examples of solving common tasks with Ruby, made short overview of nowadays Ruby developer's market and also tried to answer the main "holywar" question 'Why Ruby but not some other language?'

1. RUBY IS NOT
JUST A GEM
Ruby is also an awesome programming language.
It is a good choice for those who like and follow the
KISS principle.

2. IN THIS
PRESENTATION:
➤ Short language history
➤ Ruby’s flow
➤ Some code examples
➤ Ruby’s community
➤ Few words about nowadays problems of complex
systems development & how Ruby ships us in solving
them
➤ Your questions and my answers

3. MEET THE LIFE
STORY (SHORT
RUBY’S HISTORY
NOTES)
21 years old

4. BIRTH
1993
Matz (Yukihiro Matsumoto) wanted a language perfect for his
needs:
➤ Syntactically Simple
➤ Truly Object-Oriented
➤ Having Iterators and Closures
➤ Exception Handling
➤ Garbage Collection
➤ Portable

5. TODDLER
YEARS
December, 1996
➤ Ruby 1.0 was released
➤ Ruby 1.1 shortly followed in August of
1997
➤ The first stable version of Ruby (1.2)
was released in December of 1998.

6. PRIMARY SCHOOL
YEARS
1998-2004
➤ In 1998, Matz created a simple English homepage for Ruby - ‘Ruby-
Talk’. Ruby was beginning to spread beyond Japan.
➤ In October of 1999: the first book on the Ruby programming
language «The Object-oriented Scripting Language Ruby» by
Yukihiro Matsumoto and Keiju Ishitsuka.
➤ In 2001, the first English book on Ruby, Programming Ruby (“The
Pickaxe”), was published.
➤ Ruby 1.8 was released in 2003. This release made large amounts of
changes to the agile 10-year-old language.
➤ In 2004, RubyGems was released to the public.

7. THE REBELLIOUS
TEENAGER
2005-2012
➤ 2005: Ruby on Rails (RoR)
➤ In March of 2007, Ruby 1.8.6 was
released
➤ December, 2007: Ruby 1.9
➤ 2011: Ruby 1.9.3 (stable)

8. STRONG
ADULT
2013-nowadays
➤ February 2013: Ruby 2.0.0 was released
➤ Christmas day of 2013: Ruby 2.1.0 was released
➤ Ruby’s 21st birthday (February 24, 2014): Ruby 2.1.1
was released. Ruby is now legally allowed to drink in the
US. (Speed improvements and bugfixes).
➤ May of 2014: Ruby 2.1.2 was released (more bugfixes
and is the current stable version of Ruby).

9. FUTURE
Matz wanted a programming language that suited his needs, so
he built one. (If you can’t find something that you like, program it
yourself).
From 0.95 to 2.1.2, Ruby has struck the awe of those who wished
to program the way they wanted, not the way the machine
wanted.
We can’t know the future of the Ruby language, but we can
predict it based on the past. I believe that the Ruby language, and
its fantastic community will continue furthering the language
above and beyond what others think is possible, and projects built
using it will do the same.

10. RUBY’S FLOW
Ruby code
Ruby interpreter
jRuby
MRI

11. PEACES OF
CODE
puts ’’Hello, World!’’
1. Hello world
=> Hello, World!

12. a = 10
puts ’’now ’a’ is equal to: #{a}’’
2. String interpolation
=> now ’a’ is equal to 10

13. array = [1, "a", [2, :b]]
array.first
=> 1
array.select {|e| [String, Array].include?(e) }
=> ["a", [2, :b]]
array.map &:to_s
=> ["1", "a", "[2, :b]"]
2. Play with Arrays

14. hash = {field: "2", key: [3, "4"]}
hash[:key]
=> "2"
hash.keys
=> [:field, :key]
hash.flatten
=> [:field, "2", :key, [3, "4"]]
other_hash = {field: 3, other_key: "c"}
hash.merge other_hash
=> {:field=>3, :key=>[3, "4"], :other_key=>"c"}
2. Play with Hashes

15. class Fruit
attr_reader :weight, :eaten
def initialize(weight)
@weight = weight
@eaten = false
end
def eat
if @eaten
raise "This #{class}" was already eaten"
end
@eaten = true
end
end
3. Some OOP
class Apple < Fruit
attr_reader :cultivar
def initialize(weight, cultivar)
super(weight)
@cultivar = cultivar
end
def eat
super
@weight = @weight * 0.1
end
end

16. test_apple = Apple.new(300, "Rannet")
test_apple.weight
=> 300
test_apple.cultivar
=> «Rannet»
test_apple.eaten
=> false
test_apple.eat
=> true
test_apple.weight
=> 30
test_apple.eat
=> RuntimeError: This Apple was already eaten

17. RUBY’S
COMMUNITY
➤ Ruby groups: rubyusergroups.org
➤ Ruby mailing (Ruby-Talk, Ruby-Core, Ruby-Doc, Ruby-CVS)
➤ Ruby IRC (irc://irc.freenode.net/ruby)
➤ Blogs (O’Reilly Ruby, Riding Rails, Ruby Inside, Matz’ Blog)
➤ Contribute to Ruby Core (https://github.com/ruby/ruby)
➤ Conferentions (RubyConf, RubyKaigi, …)

18. NOWADAYS
DEVELOPMENT PROBLEMS
COMPLEXITY
USERS COUNT
TIME, DEV RESOURCES
SUPPORT, COMPUTING
RESOURCES, DATA STORAGE