kvs.ex

defmodule Kvs do
  def store(key, value) do
    rpc({:store, key, value})
  end

  def start do
    Process.register spawn(fn -> loop() end), :kvs
  end

  def lookup(key) do
    rpc({:lookup, key})
  end

  defp rpc(q) do
    send :kvs, {self(), q}
    receive do
      {:kvs, reply} ->
        reply
    end
  end
    
  defp loop do
    receive do 
      {form, {:store, key, value}} ->
        Process.put key, value
        send form, {:kvs, true}
        loop()
      {form, {:lookup, key}} ->
        send form, {:kvs, Process.get key}
        loop()
    end
  end
end