There’s no reason that yield and instance_eval DSLs need to be mutually exclusive. Far from it! In Ruby we encourage options, and it’s actually quite easy to provide a way to yield OR instance_eval based on the block passed in:

yield_and_instance_eval.rb

class Page
  attr_accessor :name
  def initialize(&block)
    if block_given?
      if block.arity == 1
        yield self
      else
        instance_eval(&block)
      end
    end
  end
end

Page.new do
  name = "this is a page"
end

Page.new do |page|
  page.name = "this is a page"
end