module Unparser::DSL

def children(*names)
  define_remaining_children(names)
  names.each_with_index do |name, index|
    define_child(name, index)
  end
end

def define_child(name, index)
  define_method(name) do
    children.at(index)
  end
  private name
end

def define_group(name, range)
  define_method(name) do
    children[range]
  end
  private(name)
  memoize(name)
end

def define_remaining_children(names)
  range = names.length..-1
  define_method(:remaining_children) do
    children[range]
  end
  private :remaining_children
end