anchor.diff:  
   puts 1.even?         # <3>
   ----
  -<1> Let's add method to integers
  +<1> Let's add a method to integers
   <2> Funny fact: in Ruby's naming conventions method returning a boolean should end with `?`
   <3> Prints `false`
   
  
positive.code: :source_dir: ../sources/2017-01-01-From-Java-to-Ruby
  :hp-image: /images/logos/ruby.png
  
  One of my 2017 resolutions wille be to try different languages and see how they compare to Java.
  This is inspired by the https://pragprog.com/book/btlang/seven-languages-in-seven-weeks[7 languages in 7 weeks] book by Bruce A. Tate.
  I don't expect to learn a new language each week though, since it took me several weeks for Ruby.
  
  The first language I've tried is Ruby.
  Ruby was created by Yukihiro Matsumoto in the nineties (like Java).
  I've seen and used Ruby many times: Vagrant configuration, Logstash plugins, FluentD plugins, Rails applications...
  I used the http://rubykoans.com/[Ruby Koans] to teach myself Ruby.
  
  ## The good
  
  Ruby has a lot of syntactic sugar which makes code really easy to read, and short to write.
  
  ### Syntactic sugar everywhere
  
  The first example deals with arrays:
  [source,ruby]
  
negative.code: first, *tail = a # <2>
  ----
  <1> Prints two and three whose indices are between 1 and length-2
  <2> The array is destructured: `first` contains one and `tail` an array of two, three, four
  
  The second example shows the templating system in strings:
  [source,ruby]
  ----
  i=4
  