Introdução à Elixir
- 1. Introdução à Elixir Contexto, ecossistema e aplicações
- 2. Sobre a linguagem ● Criada em 2012 pelo José Valim -> ● Funcional ● Concorrente ● Compilada ● Interoperabilidade com Erlang ● Metaprogramação ● Polimorfismo
- 4. Quem está usando ● Discord ● Brex ● ThoughtWorks ● Globo.com ● Slack ● B2W Digital ● Adobe ● Pinterest ● etc
- 5. Elixir é bom para ● Web API/Apps ● Soft real-time (Chat Bot, Google Docs, IoT…) ● High scalability and fault tolerance ● Concurrency ● Developer happiness
- 6. Elixir não é bom para ● Number crunching * ● Any CPU bound * ● ...
- 7. O paradigma funcional λ ● Funções puras ● Imutabilidade (Variáveis, estrutura de dados) ● Composição ● Recursão ● Transparência referencial ● First class and high order functions ● Type system ● Modularidade
- 8. Erlang / OTP ● Usada em 50% dos switches de telecom ● Erlang Virtual Machine (Beam) ● Escalabilidade ● Alta disponibilidade ● Modelo de atores
- 9. Erlang / OTP ● 1986: Linguagem proprietária (Ericsson) ● 1995: OTP ("Open Telecom Platform") ● 1998: Erlang / OTP Open Sourced ● ... ● 2008: Facebook Chat ● 2010: Whatsapp ● Outros: RabbitMQ, CouchDB, Riak, Amazon SimpleDB
- 10. THE ERLANG VM: BEAM Preemptive scheduling
- 11. The Beam and Parallel Processing
- 14. Actor model Actors are defined as independent units of computation with isolated state. These units have two core characteristics: ● They can send messages asynchronously* to one another ● They have a mailbox which contains messages that they have received, allowing messages to be received at any time and then queued for processing.
- 15. What Can Actors Do ● Create new actors ● Receive messages and in response: ○ make local decisions (alter local state) ○ perform arbitrary, side-effecting action ○ send messages ○ respond to sender 0 or more times ● “Do not communicate by sharing memory; instead share memory by communicating” - Effective Go
- 16. Actor model ● Actors process messages one at a time ● State is shared only through messages ● Actors do not share memory ● It doesn’t matter if the actor that I’m sending a message to is running locally or in another node ● Actors knows other actors by identify ● Great project: https://akka.io/ (Java / Scala / JVM 😎)
- 17. Why use actors? ● Protect state ● No need for locks and synchronization ● Concurrency ● etc
- 18. Process-based actors (Erlang) 1. Everything is a process 2. Processes are strongly isolated 3. Process creation and destruction is a lightweight operation 4. Message passing is the only way for processes to interact 5. Processes have unique names 6. If you know the name of a process you can send it a message 7. Processes share no resources 8. Error handling is non-local 9. Processes do what they are supposed to do or fail http://erlang.org/download/armstrong_thesis_2003.pdf
- 19. Supervision Tree
- 20. Policies
- 21. Umbrella project
- 22. Scale to distributed system
- 23. E A ELIXIR?
- 24. Basic Types
- 30. Functions
- 31. Functions
- 32. Functions
- 33. Guards
- 35. Structs
- 37. Pattern Matching
- 40. Even More Pattern Matching
- 41. Pipe Operator |>
- 42. Simple Interop with Erlang Can easily leverage 20+ years of Erlang libraries
- 44. Loop?
- 45. Other stuff ● Modules ● Mix (tasks) ● ExUnit (tests) ● Macros ● Error Handling ● OTP Concurrency ● OTP Supervisors ● etc
- 47. Handling a HTTP request
- 48. Handling a HTTP request
- 49. Handling a HTTP request
- 50. The Elixir way
- 51. The Elixir way
- 52. Muito obrigado!