greetings.cr

require "ecr"

class Greeting
  # def wrap(tag)
  #   String.build do |str|
  #     str << "<#{tag}>"
  #     str << yield
  #     str << "</#{tag}>"
  #   end
  # end

  def wrap(tag)
    str = yield
    str << "</#{tag}>"
  end

  ECR.def_to_s "greeting.ecr"
end

puts Greeting.new.to_s

greetings.ecr

<% wrap(:div) do %>
  Hello!
<% end %>