/bmore-on-elixir

Content for Elixir talk at B'more on Rails, Nov. 10, 2015

B’more on Elixir

Sinclair Bain

Elixir

Adjustments

  • Functions not Methods
  • Modules not Classes
  • Transformations not Mutations
  • Processes not Instances
  • Message Sending not Method Calling
  • Pattern Matching not Conditionals

Functions

	
  fn -> “Hola” end
  
  fn msg -> “Hola, #{msg}!” end
  
  greet = fn msg -> “Hola, #{msg}!” end
  
  greet.(“Mundo”)
  
  “Mundo” |> greet.()

Modules

  defmodule Greeting do
    
    def hola(msg \\ “mundo”) do
      “Hola, #{msg}!”
    end
  
  end

Transformations

  • ‘copy’, ‘version’, ‘instance’
  • current state ~> new state
  • input, process, output

Processes

  • Everything runs in a process
  • Creating processes is similar to creating instances
  • Processes are identifiable
  • Processes are addressable
  • Processes are cheap

Message Sending

  • send messages to functions running in processes
  • process identifier

Pattern Matching (and Guard Clauses)

defmodule Factorial do
  def of(0), do: 1
  
  def of(n) when n > 0,
  do: n * Factorial.of(n-1)
end

Concurrent

Two queues one coffee machine:   Concurrent
Two queues two coffee machines:  Parallel

Distribution Nodes

OTP GenServers Events Supervisors Applications Agents Tasks

Tooling

  • iex
  • mix
  • hex
  • exunit
  • eex

Phoenix Web MVC Ecto Eex

$ mix local.hex

$ mix phoenix.new bmore_on_elixir
$ cd bmore_on_elixir
$ git init && git add . && git commit -m "Initial commit of B'more on Elixir app."

$ heroku create
$ heroku buildpacks:set https://github.com/gjaldon/phoenix-static-buildpack
$ heroku buildpacks:add --index 1 https://github.com/HashNuke/heroku-buildpack-elixir

$ git push heroku master