Question

I’ve made a small DSL-like program for adding drinks to an array. It’s a pretty basic example for using instance_eval and &block to create a quick program.

Here’s the program:

class Drinks
  def initialize(&block) # Initialize drinks
    @drinks = []
    instance_eval &block
  end

  def drink(d)
    @drinks << d
  end # Add drink

  def all_drinks
    puts @drinks
  end

end

add_drinks = Drinks.new do
  drink "water"
  drink "soda"
  drink "juice"
end

add_drinks.all_drinks

The plan is to make add_drinks auto-return itself so you don’t have to use add_drinks.all_drinks. Would this be possible? Thanks.

Answer 1

You can inherit Drinks from Array, so you can work with new instance as with array

class Drinks < Array
  def initialize(&block) # Initialize drinks
    instance_eval &block
  end

  def drink(d)
    self << d
  end # Add drink
end

add_drinks = Drinks.new do
  drink "water"
  drink "soda"
  drink "juice"
end

add_drinks  #  => ["water", "soda", "juice"]