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Elixir Cookbook

Elixir Cookbook

By : Paulo Pereira
4.5 (2)
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Elixir Cookbook

Elixir Cookbook

4.5 (2)
By: Paulo Pereira

Overview of this book

This book is intended for users with some knowledge of the Elixir language syntax and basic data types/structures. Although this is a cookbook and no sequential reading is required, the book’s structure will allow less advanced users who follow it to be gradually exposed to some of Elixir’s features and concepts specific to functional programming. To get the most out of this book, you need to be well versed with Erlang.
Table of Contents (11 chapters)
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10
Index

Creating a stateful server process (messages with counters)


In this recipe, we will use the same concept used in the first recipe, but we will add a counter for each type of received message. We will introduce states!

Getting ready

To get started, let's create a module named messages_with_state.ex with the following code:

defmodule MessagesWithState do

  def start_link do
    {:ok, spawn_link(fn -> wait_for_messages(0,0,0) end)}
  end

  defp wait_for_messages(pings, pongs, unknown) do
    receive do
      {"ping", caller} ->
        send caller, "pong"
        IO.puts "Received #{pings + 1} ping messages!"
        wait_for_messages(pings + 1, pongs, unknown)

      {"pong", caller} ->
        send caller, "pong"
        IO.puts "Received #{pongs + 1} pong messages!"
        wait_for_messages(pings, pongs + 1, unknown)

      {:status, _caller} ->
        IO.puts "Current status: #{pings} pings, #{pongs} pongs and #{unknown} unknown messages."

      {_, caller} ->
        IO...
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