An exploration of DCI ideas in Ruby

dci_example.rb

#!/usr/bin/env ruby

class Hero
  attr_reader :name, :provenance, :hit_points

  def initialize(name, prov, occupation_role, init_hit_points=nil)
    @name = name
    @provenance = prov
    @occupation_role = occupation_role
    @hit_points = init_hit_points || 1;
    @attributes = {}

    self.extend occupation_role
  end

  def occupation
     @occupation_role
  end

  def increment_hit_points(amount=1)
    @hit_points += 1
  end

  def decrement_hit_points(amount=1)
    @hit_points -= 1
  end

  def add_attribute(attr)
    @attributes.merge!({ attr => true })
  end

  def attributes
    @attributes.keys
  end

  def attributes_string
    @attributes.keys.join(", ") + "[#{@hit_points}] <#{occupation}>"
  end

  def remove_attribute(attr)
    @attributes.delete attr
  end

  def damage(point_loss=1, attributes=[:big, :firey])
    decrement_hit_points(point_loss)
    attributes.each{|attr| remove_attribute(attr)}
  end
end

module PlumberRole
  def occupation
    'Plumber'
  end

  def unclog_sink; end
  def unblock_toilet; end

end

module SuperheroRole
  def self.extended(klass)
  end

  def occupation
    'Superhero'
  end

  def apply_powerup(aPowerup)
    @current_powerup = aPowerup
    aPowerup.apply(self)
  end

  def remove_powerup
    @current_powerup.strip(self)
    @current_powerup = nil
  end
end

class Powerup; end

class FireflowerPowerup < Powerup;
  def apply(host)
    host.increment_hit_points
    host.add_attribute :firey
    host.add_attribute :big
  end

  def strip(host)
    host.decrement_hit_points
    host.remove_attribute :firey
    host.remove_attribute :big
  end
end

class MagicmushroomPowerup < Powerup;
  def apply(host)
    host.increment_hit_points
    host.add_attribute :big
  end

  def strip(host)
    host.decrement_hit_points
    host.remove_attribute :big
  end
end

class Game
  def initialize(name, protagonist)
    @name = name
    @hero = protagonist.extend SuperheroRole
  end

  def story
    backstory
    setting
    puts "\n" * 2
  end

  def backstory
    puts <<-EOS
      There is a man named #{@hero.name} from #{@hero.provenance}.

      He is a #{@hero.occupation}.

      #{ method = :unclog_sink; @hero.respond_to?(method) ? ( "Yes, he can " + method.to_s) : ( 'No, he cannot ' + method.to_s ) }

      He has #{@hero.hit_points} hit points

      He is #{@hero.attributes_string}
    EOS
  end

  def setting
    puts <<-EOS

      #{@hero.name} finds himself in the world of #{@name}.

      Where he must rescue Princess Toadstool from Bowser, King of the Koopa, and his minions.
    EOS
  end

  def hero_finds_powerup(aPowerup)
    @powerup = aPowerup
    @hero.apply_powerup aPowerup
  end

  def hero_loses_powerup
    @hero.remove_powerup
  end

  def hero_status
    puts @hero.attributes_string
  end

  def hero_takes_damage(enemy)
    enemy.damage(@hero)
  end

end

class Enemy; end
class Goomba < Enemy;
  def damage(hero)
    hero.damage(1)
  end
end

game_name = "Super Mario Brothers"

man = Hero.new("Mario Mario", "Brooklyn, New York", PlumberRole)
man.add_attribute 'swarthy'

puts "He starts out like a: #{ man.attributes_string } and then begins the drama that is: #{game_name}\n\n"

smb = Game.new(game_name, man)
smb.story

puts "He beings the game like"
smb.hero_status

puts "He encounters a fire flower"
smb.hero_finds_powerup( FireflowerPowerup.new )
puts "He is now: #{man.attributes_string}"

puts "He encounters a little Goomba"
smb.hero_takes_damage(Goomba.new)
puts "He is now: #{man.attributes_string}"

puts "He then encounters a Magic mushroom!"
smb.hero_finds_powerup MagicmushroomPowerup.new
puts "He is now: #{man.attributes_string}"

output.txt

He starts out like a: swarthy[1] <Plumber> and then begins the drama that is: Super Mario Brothers

      There is a man named Mario Mario from Brooklyn, New York.

      He is a Superhero.

      Yes, he can unclog_sink

      He has 1 hit points

      He is swarthy[1] <Superhero>

      Mario Mario finds himself in the world of Super Mario Brothers.

      Where he must rescue Princess Toadstool from Bowser, King of the Koopa, and his minions.


He beings the game like
swarthy[1] <Superhero>
He encounters a fire flower
He is now: swarthy, firey, big[2] <Superhero>
He encounters a little Goomba
He is now: swarthy[1] <Superhero>
He then encounters a Magic mushroom!
He is now: swarthy, big[2] <Superhero>