This is my first attempt at reproducing Html. Not working though.

html.ex

defmodule Html do

  defmacro markup(do: inner) do
    {:ok, buffer} = start_buffer
    quote do
      unquote(inner)
    end

    buffer = get_buffer
    stop_buffer
    buffer
  end

  defmacro tag(name, do: inner) do
    IO.puts "OHAI"
    quote do
      IO.puts put_buffer "<#{unquote(name)}>"
      unquote(inner)
      IO.puts put_buffer "</#{unquote(name)}>"
    end
  end

  # TODO: These should be defp's?
  def start_buffer do
    IO.puts "start buffer"
    Agent.start_link(fn -> [] end, name: __MODULE__)
  end

  def put_buffer(buffer) do
    IO.puts "OHAI"
    Agent.get_and_update(__MODULE__, {&[buffer|&1], &[buffer|&1]})
  end

  def get_buffer do
    Agent.get(__MODULE__, &(&1))
  end

  def stop_buffer do
    Agent.stop(__MODULE__)
  end

end

defmodule Foo do
  import Html

  m = markup do
    tag :div do
      tag :h1 do
        tag :text do
        end
      end

      tag :article do
        tag :h2 do
          tag :text do
          end
        end
      end
    end
  end

  IO.puts "===================="
  IO.inspect m
  IO.puts "===================="

end