The pros and cons of metaprogramming

Let’s take a look at the router example again:

blog/lib/blog_web/router.ex

defmodule BlogWeb.Router do
  # ..
  pipeline :browser do
    plug :fetch_session
    plug :accepts, ["html"]
  end
  scope "/", BlogWeb do
    pipe_through [:browser]
    get "/posts", PostController, :index
  end
end

In the preceding code example, we can easily define a /posts route that accepts html requests and routes requests to the PostController.index/2 action. The code is concise, standardized, and easy to digest.

Here are the pros of metaprogramming. Metaprogramming can do the following:

• Hide the complexity of implementation under a simple and concise layer of abstraction. This is often referred to as a DSL.
• Increase developer productivity because the amount of code that needs...