Introduction to Elixir

Lightning talk given at work.

Transcript

1. ELIXIR LET’S GET FUNCTIONAL
2. ELIXIR ABOUT ME ▸ I am on the Agronauts (John Deere) team on the 4th floor. ▸ Graduated from Purdue University in May 2016. ▸ Started at SEP in June 2016. ▸ GitHub: @mhanberg
3. CAT MY CAT
4. ELIXIR OPEN SOURCE ELIXIR DEVELOPER
5. ELIXIR WHAT IS ELIXIR? ▸ Influenced by Ruby, Erlang, and Clojure ▸ A dynamic, functional, and compiled language designed for building scalable and maintainable applications. ▸ Leverages the Erlang VM, known for running low-latency, distributed and fault-tolerant systems, while also being successfully used in web development and the embedded software domain.
6. ELIXIR WHAT IS ERLANG? ▸ Developed at Ericsson in 1986 for use in their telephone network/platform. ▸ Runs on a virtual machine called the BEAM (or Erlang VM). ▸ Functional, dynamic, used for being distributed, fault-tolerant systems. ▸ Whatsapp (bought by Facebook for $19B) is built on Erlang.
7. ELIXIR NOTABLE FEATURES ▸ Functional ▸ Immutability ▸ Concurrent ▸ Ecosystem ▸ Interoperability with Erlang
8. times2 = fn(num) -> num * 2 end times2.(3) # 6 Enum.map([1, 2, 3], fn(num) -> num * 2 end) # [ 2, 4, 6 ] Enum.map([1, 2, 3], times2) # [ 2, 4, 6 ] ELIXIR FIRST CLASS FUNCTIONS
9. ELIXIR PATTERN MATCHING, FUNCTION DEFINITIONS def small_talk(:swanson, topic) do IO.puts "How's your #{topic} doing?" end def small_talk(:fuller, _t) do IO.puts "Mr. Director, how goes the Directing?" end small_talk(:swanson, "Fantasy Canadian Football") # How's your Fantasy Canadian Football doing? small_talk(:fuller, "Doesn't matter what I put here") # Mr. Director, how goes the Directing?
10. ELIXIR PATTERN MATCHING, VALUE DECONSTRUCTION status = {:ok, "All good here!"} {:ok, msg} = status msg # "All good here!" {:error, msg} = status # ** (MatchError) no match of right hand side value: {:ok, "All good there!"} lunch_spots = ["Cancun", "Bub's", "Chipotle"] [first | the_rest] = lunch_spots first # "Cancun" the_rest # ["Bub's", "Chipotle"] The match operator "="
11. ELIXIR IMMUTABILITY num = 10 num = 11 # Reassigning is valid dict = %{SEP: "A Software Product Design & Development Company"} dict[:SEP] = "Sucks!!" # Compilation error! dict = Map.put(dict, :Mitch, "All Star Developer") # %{ # SEP: "A Software Product Design & Development Company", # Mitch: "All Star Developer" # }
12. ELIXIR RECURSION ▸ Looping is done using recursion. ▸ The BEAM utilizes Tail Call Recursion. ▸ The Enum module abstracts away enumerating over lists, with functions like Enum.map and Enum.reduce. ▸ Pattern Matching makes recursion super easy to grok.
13. ELIXIR RECURSION def print_n_times(0, msg) do IO.puts msg end def print_n_times(n, msg) do IO.puts msg print_n_times(n -1, msg) end
14. ELIXIR CONCURRENCY ▸ Everything inside the BEAM runs in a "thread". ▸ Able to handle millions of threads running simultaneously. ▸ Utilizes the Erlang framework, OTP (Open Telecom Platform) ▸ Standard library comes with an abstraction called a "GenServer"
15. ELIXIR GENSERVER ▸ "General Server" ▸ Client - Server concept, processes send messages to each other and respond appropriately. ▸ Convenient way to encapsulate state. ▸ Similar to the "Actor Pattern", which some think of as "True Object Oriented" programming.
16. ELIXIR GENSERVER defmodule Stack do use GenServer # Callbacks def handle_call(:pop, _from, [h | t]) do {:reply, h, t} end def handle_cast({:push, item}, state) do {:noreply, [item | state]} end end # Start the server {:ok, pid} = GenServer.start_link(Stack, [:hello]) # This is the client GenServer.call(pid, :pop) #=> :hello GenServer.cast(pid, {:push, :world}) #=> :ok GenServer.call(pid, :pop) #=> :world
17. ELIXIR ECOSYSTEM ▸ Rich ecosystem with many aspects built right into the core of the language. ▸ Mix - Build tool ▸ ExUnit - Unit Testing Framework ▸ ExDoc - Documentation Generation Framework ▸ Hex - Package Manager for both Erlang and Elixir
18. ELIXIR INTEROPERABILITY WITH ERLANG ▸ All standard Erlang libraries are available ▸ Some concepts aren’t available in the Elixir standard library because they are already in Erlang. ▸ Erlang modules are represented by lowercase atoms, such as :math or :timer. ▸ Gives access to Erlang Term Storage (or ETS)
19. ELIXIR POPULAR PROJECTS ▸ Phoenix - Web Framework ▸ First class support for Web Sockets/Channels ▸ Ecto - Query Builder/ORM ▸ Plug - Composable modules for web applications ▸ Nerves - Framework for embedded devices.
20. ELIXIR WANT TO LEARN MORE? ▸ https://elixir-lang.org/ ▸ www.elixirforum.com ▸ Join us on slack in #elixir! ▸ Bi-monthly meet-up, Indy Elixir (www.indyelixir.org) ▸ Come bother me at Code & Coffee on Thursdays @ 7am ▸ Follow my blog www.mitchellhanberg.com