From: w_a_x_man <w_a_x_man@...>
Date: 2010-10-02T23:25:10+09:00
Subject: Re: The beauty of Ruby through examples

On Sep 29, 1:40 pm, Adriano Ferreira <adr...@yahoo.com> wrote:
> [Note:  parts of this message were removed to make it a legal post.]
>
> Hey all,
>
> I'm about to introduce Ruby to a group of people that is not familiar to the
> language, and the approach i'd like to take is simply by distilling out a few
> sample codes. I've been collecting some from around the internet, but i'd
> appreciate your suggestions as well.
>
> I'm looking for code snippets that represent some of the beauty of Ruby
> actually, such as:
>
> # Simplicity
> # Expressiveness
> # Productivity
> # Flexibility
> # Dynamism
> # Freedom
> # Happiness
>
> Just to clear things up, here are few examples:
>
> # Simplicity
>
> vowels = %w(a e i o u)
> alfabet = ('a'..'z').to_a
> cons = alfabet - vowels
> p cons
>
> # Expressiveness
>
> hello = 'Hello Ruby'
> 5.times { puts hello }
>
> # Productivity
>
> class Person
>   # def name
>   #   @name
>   # end
>   #
>   # def name=(other)
>   #   @name = other
>   # end
>   #
>   # def age
>   #   @age
>   # end
>   #
>   # def age=(other)
>   #   @age = other
>   # end
>
>   attr_accessor :name, :age
> end
>
> john = Person.new
> john.name = 'John'
> john.age = 25
> p john
>
> # Flexibility
>
> class Array
>   def pick
>     self[rand(self.size)]
>   end
>
>   alias :choose :pick
> end
>
> puts %w(1 2 3 4 5).pick
> puts %w(1 2 3 4 5).choose
>
> # Dynamism
>
> Padawan = Class.new
>
> class Jedi
>   def train(padawan)
>     def padawan.control_the_force
>       puts "Now i'm ready to become a Jedi!"
>     end
>   end
> end
>
> skywalker = Padawan.new
> yoda = Jedi.new
> p skywalker.respond_to? :control_the_force  # => false
>
> yoda.train skywalker
> p skywalker.respond_to? :control_the_force  # => true
> skywalker.control_the_force# => Now i'm ready to become a Jedi!
>
> ..and so on.
>
> Any more examples?
>
> Thanks in advance,
>
> Adriano

In comp.lang.lisp, this elisp code was posted as an example
of how to shuffle a vector:

(defun emms-shuffle-vector (vector)
  "Shuffle VECTOR."
  (let ((i (- (length vector) 1)))
    (while (>= i 0)
      (let* ((r (random (1+ i)))
             (old (aref vector r)))
        (aset vector r (aref vector i))
        (aset vector i old))
      (setq i (- i 1))))
  vector)

Ruby:

(9..20).sort_by{ rand }
    ==>[15, 14, 12, 18, 16, 10, 9, 13, 11, 20, 17, 19]