Elixir - Simple agent-based counter

agent_counter.exs

# Put this code inside a function to easily count the number of times the
# function is called.

# Create the agent
agent_process_name = :your_agent

if Process.whereis(agent_process_name) == nil do
  {:ok, a} = Agent.start_link(fn -> 0 end)
  Process.register(a, agent_process_name)
end

# Increment the counter
Agent.update(agent_process_name, fn state -> state + 1 end)

# To get the count, run: Agent.get(_your_agent_process_name = :your_agent, & &1)