Introducción a Elixir

@solojavier

@solojavier

Qué
es
Elixir

Funcional

EVM

Extensible

Sintaxis similar a Ruby

Qué

dicen de
Elixir

I [looked at Elixir again], and I felt the same way I felt when I first saw Ruby.

Dave Thomas

Elixir is what would happen if Erlang, Clojure, and Ruby somehow had a baby and it wasn’t an accident.

Devin Torres

Elixir offers developers the functional power and concurrent resilience of Erlang, with friendlier syntax, libraries and metaprogramming

Simon St. Laurent

It didn’t take long, but pretty soon my gut feeling kicked in. This is good shit.

Joe Armstrong

Having a pretty syntax wrapped around the powerful Erlang VM seems to be an irresistible combination.

Benjamin Tan

I liked everything I saw in Erlang, but I hated the things that I didn’t see.

Jose Valim

Porqué
usar
Elixir

Pensar dyferente

Curva de aprendizaje

Inmutabilidad

Concurrencia

Erlang

Adaptable

Performance

Tolerante a fallos

Herramientas

Comunidad

Pipes!

Pipes!

def fetch(user, project) do
  handle_response(HTTPoison.get(issues_url(user, project), @user_agent))
end

Pipes!

def fetch(user, project) do
  url      = issues_url(user, project)
  response = HTTPoison.get(url, @user_agent)
  handle_response(response)
end

Pipes!

def fetch(user, project) do
  issues_url(user, project)
    |> HTTPoison.get(@user_agent)
    |> handle_response
end

Como

se ve
Elixir

defmodule Times do
  def double(n),    do: n * 2
  def triple(n),    do: n * 3
  def quadruple(n), do: n * 4
end

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

message = fn
  0, 0, _ -> "FizzBuzz"
  0, _, _ -> "Fizz"
  _, 0, _ -> "Buzz"
  _, _, n -> "#{n}"
end

fizz_buzz = fn
  n -> message.(rem(n, 3), rem(n, 5), n)
end

defmodule MathTest do
  use ExUnit.Case, async: true

  test "can add two numbers" do
    assert 1 + 1 == 2
  end
end

parent = self()

# Spawns an Elixir process
spawn_link(fn ->
  send parent, {:msg, "hello world"}
end)

# Block until the message is received
receive do
  {:msg, contents} -> IO.puts contents
end

Cómo

utilizar
Elixir

mix

mix new

* creating README.md
* creating .gitignore
* creating mix.exs
* creating config
* creating config/config.exs
* creating lib
* creating lib/kv.ex
* creating test
* creating test/test_helper.exs
* creating test/kv_test.exs

mix.exs

defmodule KV.Mixfile do
  use Mix.Project

  def project do
    [app: :kv,
     version: "0.0.1",
     deps: deps]
  end

  def application do
    [applications: [:logger]]
  end

  defp deps do
    []
  end
end

mix compile

Compiled lib/kv.ex
Generated kv.app

mix test

1) test the truth (KVTest)
   test/kv_test.exs:4
   Assertion with == failed
   code: 1 + 1 == 3
   lhs:  2
   rhs:  3
   stacktrace:
     test/kv_test.exs:5

Finished in 0.05 seconds
1 tests, 1 failures

mix help

mix                   # Run the default task (current: mix run)
mix archive           # List all archives
mix archive.build     # Archive this project into a .ez file
mix archive.install   # Install an archive locally
mix archive.uninstall # Uninstall archives
mix clean             # Delete generated application files
mix cmd               # Executes the given command
mix compile           # Compile source files
mix compile.protocols # Consolidates all protocols in all paths
mix deps              # List dependencies and their status
mix deps.clean        # Remove the given dependencies' files
mix deps.compile      # Compile dependencies
mix deps.get          # Get all out of date dependencies
mix deps.unlock       # Unlock the given dependencies
mix deps.update       # Update the given dependencies
mix do                # Executes the tasks separated by comma
mix docs              # Generate documentation for the project
mix escript.build     # Builds an escript for the project
mix eunit             # Run a project's eunit tests
mix help              # Print help information for tasks
mix hex.config        # Read or update hex config
mix hex.docs          # Publish docs for package
mix hex.info          # Print hex information
mix hex.key           # Hex API key tasks
mix hex.owner         # Hex package ownership tasks
mix hex.publish       # Publish a new package version
mix hex.search        # Search for package names
mix hex.user          # Hex user tasks
mix loadconfig        # Loads and persists the given configuration
mix local             # List local tasks
mix local.hex         # Install hex locally
mix local.rebar       # Install rebar locally
mix new               # Create a new Elixir project
mix run               # Run the given file or expression
mix test              # Run a project's tests
iex -S mix            # Start IEx and run the default task

hex

mix.exs

defp deps do
    [{:ecto, "~> 0.1.0"},
     {:postgrex, "~> 0.3.0"},
     {:cowboy, github: "extend/cowboy"}]
end

mix deps.get

* Updating ex_doc (git://github.com/elixir-lang/ex_doc.git)
remote: Counting objects: 46, done.
remote: Compressing objects: 100% (17/17), done.
remote: Total 46 (delta 7), reused 4 (delta 4), pack-reused 25
From git://github.com/elixir-lang/ex_doc
   fa2feac..214afbb  master     -> origin/master
 * [new tag]         v0.7.2     -> v0.7.2
A new Hex version is available (v0.7.5), please update with `mix local.hex`
Running dependency resolution
Unlocked:   httpoison, jsx, earmark
Dependency resolution completed successfully
  httpoison: v0.6.2
  ssl_verify_hostname: v1.0.4
  idna: v1.0.2
  jsx: v2.6.1
  hackney: v1.1.0
  earmark: v0.1.16
* Updating jsx (Hex package)
Checking package (https://s3.amazonaws.com/s3.hex.pm/tarballs/jsx-2.6.1.tar)
Fetched package
Unpacked package tarball (/Users/javier/.hex/packages/jsx-2.6.1.tar)
* Updating earmark (Hex package)
Checking package (https://s3.amazonaws.com/s3.hex.pm/tarballs/earmark-0.1.16.tar)
Fetched package
Unpacked package tarball (/Users/javier/.hex/packages/earmark-0.1.16.tar)
* Updating hackney (Hex package)
Checking package (https://s3.amazonaws.com/s3.hex.pm/tarballs/hackney-1.1.0.tar)
Fetched package
Unpacked package tarball (/Users/javier/.hex/packages/hackney-1.1.0.tar)
* Updating ssl_verify_hostname (Hex package)
Checking package (https://s3.amazonaws.com/s3.hex.pm/tarballs/ssl_verify_hostname-1.0.4.tar)
Fetched package
Unpacked package tarball (/Users/javier/.hex/packages/ssl_verify_hostname-1.0.4.tar)

hex.pm

iEx

iex

Erlang/OTP 17 [erts-6.3.1] [source] [64-bit] [smp:8:8] [async-threads:10] [hipe] [kernel-poll:false] [dtrace]

Interactive Elixir (1.0.3) - press Ctrl+C to exit (type h() ENTER for help)
iex(1)> IO.puts "Hello World"
Hello World
:ok
iex(2)> import_file "~/.iex.exs"

iex(3)> [1, 2, 3, 4, 5]
[1,2,3,...]

ExUnit

ExUnit

defmodule CliTest do
  use ExUnit.Case
  import Issues.CLI, only: [
    parse_args: 1
  ]

  test ":help returned by option parsing with -h and --help options" do
    assert parse_args(["-h", "anything"]) == :help
    assert parse_args(["--help", "anything"]) == :help
  end

  test "three values returned if three given" do
    assert parse_args(["user", "project", "99"]) == { "user", "project", 99 }
  end

  test "count is defaulted if two values given" do
    assert parse_args(["user", "project"]) == { "user", "project", 4 }
  end
end

ExUnit

Compiled lib/issues.ex
Compiled lib/issues/cli.ex
Compiled lib/issues/github_issues.ex
Compiled lib/issues/table_formatter.ex
Generated issues.app
..............

Finished in 0.1 seconds (0.1s on load, 0.00s on tests)
14 tests, 0 failures

Randomized with seed 399755

ExDoc

ExDoc

ExDoc

1) test doc at Issues.TableFormatter.split_into_columns/2 (4) (DocTest)
     test/doc_test.exs:3
     Doctest failed
     code: list = [Enum.into([{"a", "1"},{"b", "2"},{"c", "3"}], HashDict.new),
                    Enum.into([{"a", "4"},{"b", "5"},{"c", "6"}], HashDict.new)]
            Issues.TableFormatter.split_into_columns(
                list, [ "b", "b", "c" ]) === [ ["1", "4"], ["2", "5"], ["3", "6"] ]
     lhs:  [["2", "5"], ["2", "5"], ["3", "6"]]
     stacktrace:
       lib/issues/table_formatter.ex:38: Issues.TableFormatter (module)

defmodule DocTest do
  use ExUnit.Case
  doctest Issues.TableFormatter
end

ExDoc

Phoenix framework

Phoenix Framework

Phoenix Framework

$ mix archive.install https://github.com/phoenixframework/.../phoenix_new-0.13.0.ez

$ mix phoenix.new hello_phoenix

$ cd hello_phoenix
$ mix phoenix.server

Phoenix Framework

Cómo

aprender
Elixir

Elixir-Lang.org

Programming Elixir

Introducing Elixir

h4cc/awesome-elixir

ElixirConf

comunidad.softcraft.mx

ElixirGDL