Trivial Example of a the Recipe creation

recipe.rb

module Measurements
  def cup
    self * 48
  end
  
  alias_method :cups, :cup
  
  def tsp ; self ; end
  alias_method :tsps, :tsp
  
  def dozen ; self * 12 ; end
  alias_method :dozens, :dozen
end

class Fixnum
  include Measurements
end

class Float
  include Measurements
end


class Ingredient
  
  attr_reader :name, :amount, :preparation
  
  def initialize(name,amount,preparation = "")
    @name = name
    @amount = amount
    @preparation = preparation
  end
  
end

class Cookbook
  
  attr_reader :recipes
  
  def self.recipe(name,&block)
    
    @recipes ||= []
    recipe = Recipe.new(name)
    recipe.instance_eval(&block)
    @recipes << recipe
    recipe
    
  end
end

module MarkdownRenderer
  def to_markdown
    formatted_ingredients = @ingredients.map do |name,i|
      "* #{i.amount} tsps of #{i.name}"
    end.join("\n")
    
    formatted_instructions = @instructions.map {|i| "* #{i}" }.join("\n")
    
    "# #{name}\n\n" +
    "#{serves}\n\n" +
    "## Ingredients\n\n" +
    formatted_ingredients +
    "\n\n## Instructions\n\n" +
    formatted_instructions
  end
  
end


class Recipe
  
  attr_reader :name
  
  def initialize(name)
    @name = name
  end
  
  attr_reader :ingredients
  
  def ingredient(name,amount,preparation = "")
    #puts "Adding #{name} in amount #{amount} with preparation #{preparation}"
    @ingredients ||= {}
    @ingredients[name] = Ingredient.new name, amount, preparation
    
  end
  
  attr_reader :instructions
  
  def instruction(message)
    #puts "Instruction: #{message}"
    @instructions = []
    @instructions << message
  end
  
  def serves(amount = nil,unit = nil)
    if amount and unit
      @serves = "Serving up #{amount} of #{unit}! Hot and Fresh!"
    else
      @serves
    end
  end
  
  def half
    0.5
  end
  
  include MarkdownRenderer
  
  
end


cookie_recipe = Cookbook.recipe "Chocolate Chip Cookies" do
  
  ingredient "butter", 1.cup, "softened"
  ingredient "salt", half.tsp
  ingredient "semisweet chocolate chips", 2.cups
  
  instruction "Preheat oven to 350 degrees F (175 degrees C)."
  
  serves 4.dozen, "cookies"
  
end

puts cookie_recipe.to_markdown