I think most of the GoF can be implemented in elixir. In ruby, many of them are made trivial via metaprogramming, the same would be true in elixir. I have used the Strategy pattern, and am currently working on a Bridge pattern. I would recommend posting a github page for submissions on independent libraries, or some way of compiling a collection from the community. Could be really useful. What do people think of this Strategy ?
# start server with default formatter
defmodule Report do
use GenServer
def start_link(formatter) do
GenServer.start_link(__MODULE__, formatter, name: __MODULE__)
end
def init(formatter), do: {:ok, formatter}
def handle_call({:output_report, context}, _from, formatter) do
formatter.output_report(context)
{:reply, :ok, formatter}
end
def handle_call({:change_format, new_formatter}, _from, _state),
do: {:reply, :ok, new_formatter}
# Public APIs
def output_report(context),
do: GenServer.call(__MODULE__, {:output_report, context})
def change_format(formatter),
do: GenServer.call(__MODULE__, {:change_format, formatter})
end
defmodule Activities do
def output_report(context) do
IO.puts("***** #{context.title} *****")
Enum.each(context.text, &IO.puts/1)
end
end
{:ok, _} = Report.start_link(Activities)
context = %{
title: "Monthly Report",
text: ["Things are going", "really, really well"]
}
# Change the formatter at runtime
Activities.output_report(context)
