Dynamic builder config

BuilderConfig.rb

require 'docile'
require 'linguistics'

Linguistics.use :en

class BuilderConfig

  def initialize
    @paths = @@paths
    @versions = @@versions
  end

  def self.defaults(&block) Docile.dsl_eval(self, &block) end
  def eval(&block) Docile.dsl_eval(self, &block) end

  @@paths = {}
  def self.set_path(k,v) @@paths[k] = v end
  def set_path(k,v) @paths[k] = v end
  def path(k, *append_paths) File.join( @paths[k], *append_paths ) end
  attr_accessor :paths

  @@versions = {}
  def self.set_version(k,v) @@versions[k] = v end
  def set_version(k,v) @versions[k] = v end
  def version(k) @versions[k] end
  attr_accessor :versions

  def self.set_value(name, value)
    class_variable_set "@@#{name}", value
    define_method(name) { value }
  end

  def set_value(name, value)
    instance_variable_set "@#{name}", value
    define_singleton_method(name) { value }
  end

end

UseExample.rb

BuilderConfig.defaults do
  set_version :component1, '1.1'
  set_version :component2, '2.2'
  set_path :global, 'Global'
  set_value :global_value, "global default value"
end

config = BuilderConfig.new.eval do
  set_version :component3, '3.3'
  set_path :local, 'Local'
  set_value :local_value, "Some value for this instance only."
end

config.eval do

  puts path :global, 'sub', 'two'
  #=> Global/sub/two

  puts path :local, 'sub', 'two'
  #=> Local/sub/two

  puts global_value
  #=> global default value

  puts local_value
  #=> Some value for this instance only.

  puts version :component1
  #=> 1.1

  puts version :component2
  #=> 2.2

  puts version :component3
  #=> 3.3

  puts inspect
  #=> #<BuilderConfig:0x007fd41392e2c8
  #     @paths={:global=>"Global", :local=>"Local"},
  #     @versions={:component1=>"1.1", :component2=>"2.2", :component3=>"3.3"},
  #     @local_value="Some value for this instance only."
  #     >

end