Macro wrapper for fetching default value of map

gistfile1.ex

defmodule Fetcher do
  def db_value_for(key) do
    IO.puts "processing..."
    "db value for #{key}"
  end

  defmacro get(map, key, default \\ nil) do
    quote do
      case Map.get(unquote(map), unquote(key)) do
        nil   -> unquote(default)
        value -> value
      end
    end
  end

  def run do
    map = %{x: 1}
    IO.puts get(map, :x, db_value_for(:x))
    IO.puts get(map, :z, db_value_for(:z))
  end
end

Fetcher.run()

# iex(2)> Fetcher.run()
# 1
# processing...
# db value for z
# :ok