Elixir - Easy fun for busy developers @ Devoxx 2016

#Devoxx #AwesomeElixir @koenighotze

Bootstrap |> Elixir

EASY FUN FOR BUSY DEVELOPERS


@koenighotze / David Schmitz

Senacor Technologies Programmer!

Bad, bad fighter!


WET YOUR APPETITE FOR ELIXIR SHOW OFF SOME COOL FEATURES

CODE A DISTRIBUTED PIZZA PARLOUR


学⼀一⻔门语⾔言，就是多⼀一个观察世界的窗户。To learn a language is to have one more window from which to look at the world


Two minor caveats


I AM THE JON SNOW OF ELIXIR AND ERLANG/OTP


THIS IS NOT A README!


YET ANOTHER PROGRAMMING LANGUANGE?

Y A P L


Elixir in a Nutshell

+Elixir in a Nutshell

+


Principle of Conciseness Principle of Consistency Principle of Flexibility

Why Ruby is awesome


Battle-proven BEAM and OTP

Ever seen WhatsApp crash?

Reactive before Reactive-is-HipTm

Actors before Actors-are—HipTm

Why Erlang is awesome


Why Clojure is awesome

Because Rich Hickey is always right


WHY NOT JUST USE RUBY, ERLANG OR CLOJURE?


It didn't take long, but pretty soon my gut feeling kicked in. This is good $hit. …, they both compile to instructions for the EVM

- Joe Armstrong (Creator of Erlang)


Programmer focussed OTP Power + Ruby Love Functional but pragmatic

Standard Toolset

Why Elixir is awesome


Erlang/OTP

ERLANG/BEAM TOOLS

LIBRARIES PATTERNS


Elixir

ERLANG/BEAM TOOLS

LIBRARIES PATTERNS


Pizza Parlour - Version 1“Take my money! I want a salami pizza!”

“I am hungry!!”

“3 €, please!”


Pizza Parlour - Version 1 Demo


WHAT ABOUT 99.9999999?


Pillars of Resilience and ReliabilityMessage-passing between

isolated processes Automatic recovery and

monitoring Transparent distribution


Elixir Power Tools

Messaging with GenServer modules Supervisor for transparent resilience


Shared resources Shared state Shared stability

SHARED STATE

COMPUTATION COMPUTATION COMPUTATION

HEAVY WEIGHT PROCESS

COMPUTATION COMPUTATION COMPUTATION


Light Weight Processes

MAILBOX

STATE

COMPUTATION

AsynchronousSynchronous

GENSERVER


GenericServer in a Nutshell

loop(current_state): wait for message handle message send reply loop(new_state)


Architecture build around tiny Processes

PROCESS

PROCESS

PROCESS

PROCESS

PROCESS

PROCESS

PROCESS

PROCESS

PROCESS

PROCESS

PROCESS

HEAVY WEIGHT PROCESS


Message driven Pizza - The request{:pizza, “Salami”}

handle_call({:pizza, “Salami”}, from, state)


%{order_number: 123, price: 10.50}

Message driven Pizza - The reply


NOW REALLY, WHAT ABOUT

RESILIENCE???


“HAVE YOU TRIED TURNING IT OFF AND ON AGAIN?”


The WHAT IF scenario

{:pizza, “Salami”}


Risk at the Bottom of the Supervision TreeAPPLICATION

SUPERVISOR

Here be dragons…


APPLICATION

SUPERVISOR

Supervisors watch their Children


There is so much more


Protocols for polymorphism

defimpl String.Chars do def to_string(bitmap), for: [Bitmap] do … end end


Hygienic Macrosdefmacro unless(clause, do:expression) do quote do if(!unquote(clause) do unquote(expression)) end end end


Zero downtime Hot code replacement

def code_change(ver, old_state, extra) do new_state = … {:ok, new_state} end


Real-time apps with Ecto and Phoenix

defmodule Video do def alphabetical(query) do from q in query, order_by: q.name end end


Real-time apps with Ecto and Phoenix

def alphabetical(query) do …

Video |> Video.alphabetical |> Repo.all


SHOULD WE ALL START BUILDING EVERYTHING

WITH ELIXIR?


WELL….MAYBE NOT?!


AND OF COURSE…


MICROSERVICE AND CLOUD READY ;)


New insights and ideas Clean patterns as part of the core Architecture and Tooling for IoT Vibrant and friendly Community

Come for OTP, stay for…


Elixir Homepage, http://elixir-lang.org/

Dave Thomas, Programming Elixir

Fred Hebert, Stuff Goes Bad: Erlang in Anger

Do you want to know more?

http://elixir-lang.org/


Thank you very much!<[email protected]>

Elixir - Easy fun for busy developers @ Devoxx 2016

Engineering

Transcript of Elixir - Easy fun for busy developers @ Devoxx 2016