かなり雑だけど張っておく 擬似的な生態系を作ってみる

ecosys.rb

# -*- coding: utf-8 -*-

module Ecosys

  extend self

  class FoodWeb

    def initialize
      @creatures = []
      @mutual = []
    end

    attr_reader :creatures
    attr_reader :mutual

    def inspect
      @creatures.map do |c|
        filter(c).map(&:inspect).join "\n"
      end.join "\n\n#{'='*40}\n"
    end

    def << creature
      add_creature creature
      add_mutual creature
      creature
    end

    def filter c, d=nil
      r = @mutual.select { |m| m.c == c or m.d == c }
      return r if d.nil?
      r.select { |m| m.c == d or m.d == d }
    end

    def changed c
      # 絶滅
      if c.n <= 0
        @creatures.delete c
        @mutual.delete_if do |m|
          m.c == c or m.d == c
        end
      end
    end

    def add_mutual c
      @creatures.each do |d|

        if c.descent.nil?
          @mutual << Mutual.new(c, d, Effect.friend)
          next
        end

        # 近縁の種であれば共生を選択する
        if c == d or c.descent == d or c.descent.ascents.include? d
          @mutual << Mutual.new(c, d, Effect.friend)
          next
        end

        # 近隣の種でなくなったら性質をランダムに変更する
        if c.descent.descent.nil? or c.descent.descent == d or c.descent.descent.ascents.include? d
          @mutual << Mutual.new(c, d, Effect.sample)
          next
        end

        desm = c.descent.mutualof d
        if desm.nil?
          @mutual << Mutual.new(c, d, Effect.sample) # 通常ここは処理されない
        elsif rand(4) == 0
          @mutual << Mutual.new(c, d, Effect.sample) # 一部の性質は変化する
        else
          @mutual << Mutual.new(c, d, desm.effect) # 基本的には親の性質を受け継ぐ
        end
      end
    end

    def add_creature c
      @creatures << c
    end

    private :add_mutual, :add_creature

    class Effect

      def initialize text, &action
        @text = text
        @action = action
      end

      def call *a, &b
        @action.call *a, &b
      end

      def to_s
        @text
      end

      def to_proc
        @action
      end

      FRIEND = Effect.new "they are friend." do |c, d|
        if [true, false].sample then
          c.n -= 1
          c.food_web.changed c
          d.breed
        else
          d.n -= 1
          d.food_web.changed d
          c.breed
        end
      end

      def self.friend
        [FRIEND].sample
      end

      LEFT_EAT = Effect.new "left eat right" do |c, d|
        c.eat d
      end

      RIGHT_EAT = Effect.new "right eat left" do |c, d|
        d.eat c
      end

      SYMBIOSIS = Effect.new "symbiosis" do |c, d|
        c.breed
        d.breed
      end

      def self.sample
        [LEFT_EAT, RIGHT_EAT, SYMBIOSIS].sample
      end

    end

    class Mutual

      def initialize c, d, effect
        @c = c
        @d = d
        @effect = effect
      end

      attr_reader :c, :d
      attr_reader :effect

      def call
        effect.call c, d
      end

      def inspect
        "#{@c}, #{@d}; #{@effect}"
      end

      def to_proc
        method(:call).to_proc
      end

    end

  end

  class Creature

    NAMES = [
      'ar', 'af', 'dor', 'imd', 'rus', 'wa', 'fa', 'wi', 'mma', 'be', 'ry', 'jara', 'je'
    ]

    def initialize descent=nil, n=1
      @n = 1
      if descent.nil?
        @descent = nil
        @name = ''
        @name_words = []
        @food_web = FoodWeb.new
        @food_web << self
        return
      end

      @descent = descent

      if descent.name_words.length > 6
        [descent.name_words[1..-1], NAMES.sample].tap do |oldn, newn|
          @name = oldn.join + newn
          @name_words = oldn + [newn]
        end
      else
        NAMES.sample.tap do |newn|
          @name = descent.name + newn
          @name_words = descent.name_words + [newn]
        end
      end

      @food_web = descent.food_web
      @food_web << self
    end

    def eat other
      other.n -= 1
      breed
      food_web.changed other
      food_web.changed self
      self
    end

    def breed
      if rand(7) > 0 # 1/7 で進化
        self.n += 1
        self
      else
        create
      end
    end

    def create
      Creature.new self
    end

    def ascents
      @food_web.creatures.select do |c|
        c.descent == self
      end
    end

    def mutualof d
      @food_web.filter(self, d).first
    end

    def to_s
      inspect
    end

    def inspect
      "<#[#{@n}]: #{@name} from #{@descent.name if @descent}:C>"
    end

    attr_accessor :n
    attr_reader :name, :name_words
    attr_reader :descent
    attr_reader :food_web

  end

end

main.rb

# -*- coding: utf-8 -*-

require './ecosys'

include Ecosys

common_descent  = Creature.new nil, 10

# 最初の生物を生み出す
5.times do
 a =  Creature.new common_descent, 10
 4.times do 
   b = Creature.new a, 10
   5.times do
     c = Creature.new b, 10
   end
  end
end

food_web = common_descent.food_web
c = 100
loop do 
  food_web.mutual.sample.call
  c -= 1
  if c < 0
    c = 100
    puts "="*40
    puts food_web.creatures.join "\n"
  end
end