what is this elixir thing everyone is talking about

some of my fav features of elixir

lightning talk for CodeDaze.io on September 16th, 2016

Transcript

1. what is this elixir thing
   everyone's talking about
   by jojo
   

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2. what is elixir
   

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3. elixir is a functional language
   

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4. created by José Valim
   

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5. that runs on the erlang vm
   

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6. pattern matching
   iex(1)> [first, second] = [1, 2]
   [1, 2]
   iex(2)> first
   1
   

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7. pattern matching
   iex(2)> [first, second] = [1,2,3]
   ** (MatchError) no match of right hand side
   value: [1, 2, 3]
   

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8. pattern matching
   iex(1)> payload = %{username: "eljojo", stuff: true}
   %{stuff: true, username: "eljojo"}
   iex(2)> %{username: name} = payload
   %{stuff: true, username: "eljojo"}
   iex(3)> name
   "eljojo"
   

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9. function overloading
   def make_sound(:cow) do
   IO.puts "MOOOOOOOOO"
   end
   def make_sound(:cat) do
   IO.puts "MEEEOOWW"
   end
   def make_sound(_) do
   IO.puts "¯\_(ϑ)_/¯"
   end
   

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10. function overloading
    def make_sound(%{animal: :cow}) do
    IO.puts "MOOOOOOOOO"
    end
    def make_sound(%{animal: :cat}) do
    IO.puts "MEEEOOWW"
    end
    def make_sound(%{animal: name}) do
    IO.puts "not sure how to #{name} ¯\_(ϑ)_/¯"
    end
    

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11. we also got guards
    def page_ops(downtime) when downtime < 10 do
    IO.puts "¯\_(ϑ)_/¯"
    end
    def page_ops(downtime) when downtime >= 10 do
    PagerDuty.notify(whatever)
    end
    

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12. pipe operator
    def add_one(number), do: number + 1
    def multiply_by_three(number), do: number * 3
    multiply_by_three(add_one(1)) # => 6
    

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13. pipe operator
    def add_one(number), do: number + 1
    def multiply_by_three(number), do: number * 3
    1 |> add_one |> multiply_by_three # => 6
    

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14. processes + messages
    current_process = self()
    spawn_link(fn ->
    send(current_process, {:msg, "hello world"})
    end)
    receive do
    {:msg, contents} -> IO.puts contents
    end
    

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15. processes + messages
    # machine one
    receive do
    {:msg, contents} -> IO.puts contents
    end
    # machine two
    process_name = "$MACHINE_ONE"
    spawn_link(fn ->
    send(process_name, {:msg, "yo!"})
    end)
    

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16. what is phoenix
    

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17. A productive web framework that
    does not compromise speed and maintainability.
    

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18. it's basically rails for
    elixir, but cooler
    

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19. validations
    def changeset(struct, params \\ %{}) do
    struct
    |> cast(params, [:email_address, :first_name])
    |> validate_required([:email_address])
    end
    def changeset_after_signup(struct, params \\ %{}) do
    changeset(struct, params)
    |> validate_required([:first_name])
    end
    

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20. we're hiring!
    

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21. @eljojo
    

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