Hello, Joe. Hello, Mike; Hello, Robert.1

A Hello World Style Lighting Talk on Erlang.

1. From Erlang the Movie (https://archive.org/details/ErlangTheMovie)

https://archive.org/details/ErlangTheMovie

Hello, Erlang.

Erlang and OTP was designed for building distributed, asynchronous, highly-concurrent, fault

tolerant applications with high availability.

Hello, Erlang.

Erlang and OTP was designed for building distributed, asynchronous, highly-concurrent, fault

tolerant applications with high availability.

#BuzzwordBingo

Hello, Telecom.

Hello, Telecom.

100s of Thousands, if not Millions, of calls happen at the same time

Hello, Telecom.

100s of Thousands, if not Millions, of calls happen at the same time

Your phone line has to always be available

Hello, Telecom.

100s of Thousands, if not Millions, of calls happen at the same time

Your phone line has to always be available

My call cannot corrupt your call

Hello, Dj vu

Hello, Dj vu

Sound Familiar?

Hello, Internet!

Hello, Failure.

Hello, Failure. In the Real World things fail. Embrace it.

Hello, Failure. In the Real World things fail. Embrace it.

Let It Crash philosophy

Hello, Failure. In the Real World things fail. Embrace it.

Let It Crash philosophy

Immutability

Hello, Failure. In the Real World things fail. Embrace it.

Let It Crash philosophy

Immutability

No Shared State

Hello, Failure. In the Real World things fail. Embrace it.

Let It Crash philosophy

Immutability

No Shared State

Isolated Processes Communicate Through Message Passing (Actor Model)

Hello, Failure. In the Real World things fail. Embrace it.

Let It Crash philosophy

Immutability

No Shared State

Isolated Processes Communicate Through Message Passing (Actor Model)

Supervision Hierarchy

Hello, Failure. In the Real World things fail. Embrace it.

Let It Crash philosophy

Immutability

No Shared State

Isolated Processes Communicate Through Message Passing (Actor Model)

Supervision Hierarchy

Live code reloading

Hello, C10k Problem.

Hello, C10k Problem.

Hello, C10k Problem.

Alan Kay

Ithoughtofobjectsbeinglikebiologicalcells and/orindividual

computersonanetwork,onlyableto communicatewithmessages [].2

Hello, OOP.

2. http://userpage.fu-berlin.de/~ram/pub/pub_jf47ht81Ht/doc_kay_oop_en

http://userpage.fu-berlin.de/~ram/pub/pub_jf47ht81Ht/doc_kay_oop_en

Hello, Weaknesses.

Hello, Weaknesses. No strings as a data type

Hello, Weaknesses. No strings as a data type

List of Integers or Binary types

Hello, Weaknesses. No strings as a data type

List of Integers or Binary types

Not super performant for string manipulation, but good enough for most scenarios

Hello, Weaknesses. No strings as a data type

List of Integers or Binary types

Not super performant for string manipulation, but good enough for most scenarios

Not great for GUIs

Hello, Weaknesses. No strings as a data type

List of Integers or Binary types

Not super performant for string manipulation, but good enough for most scenarios

Not great for GUIs

Not going to be run on your mobile device;

Hello, Weaknesses. No strings as a data type

List of Integers or Binary types

Not super performant for string manipulation, but good enough for most scenarios

Not great for GUIs

Not going to be run on your mobile device;

but great for you mobile device backend.

Hello, Weaknesses. No strings as a data type

List of Integers or Binary types

Not super performant for string manipulation, but good enough for most scenarios

Not great for GUIs

Not going to be run on your mobile device;

but great for you mobile device backend.

WhatsApp anyone?

Hello, Weaknesses. No strings as a data type

List of Integers or Binary types

Not super performant for string manipulation, but good enough for most scenarios

Not great for GUIs

Not going to be run on your mobile device;

but great for you mobile device backend.

WhatsApp anyone?

Not insanely fast

Hello, Weaknesses. No strings as a data type

List of Integers or Binary types

Not super performant for string manipulation, but good enough for most scenarios

Not great for GUIs

Not going to be run on your mobile device;

but great for you mobile device backend.

WhatsApp anyone?

Not insanely fast

"There's no such thing as fast, only fast enough" ~ Joe Armstrong

Hello, FizzBuzz.

Hello, fizzbuzz.erl-module(fizzbuzz).

-export([fizzbuzz/1]).

fizzbuzz(N) -> Translations = lists:map(fun translate/1, lists:seq(1, N)), lists:foreach(fun(Item) -> io:format("~s~n", [Item]) end, Translations).

translate(N) when N rem 3 =:= 0 andalso N rem 5 =:= 0 -> 'FizzBuzz'; translate(N) when N rem 3 =:= 0 -> 'Fizz'; translate(N) when N rem 5 =:= 0 -> 'Buzz'; translate(N) -> integer_to_list(N).

Hello, fizzbuzz.ex

defmodule FizzBuzz do def fizzbuzz(n) do 1..n |> Enum.map(&translate/1) |> Enum.join("\n") |> IO.puts end

def translate(n) when rem(n, 3) == 0 and rem(n, 5) == 0, do: :FizzBuzz def translate(n) when rem(n, 3) == 0, do: :Fizz def translate(n) when rem(n, 5) == 0, do: :Buzz def translate(n), do: n end

Hello, fizzbuzz.lfe(defmodule fizzbuzz (export (fizzbuzz 1)))

(defun fizzbuzz (n) (lists:foreach (lambda (term) (lfe_io:format "~p~n" `(,term))) (translate-upto n)))

(defun translate-upto (n) (let ((numbers (lists:seq 1 n))) (lists:map (lambda (n) (translate n (rem n 3) (rem n 5))) numbers)))

(defun translate ([_ 0 0] 'FizzBuzz) ([_ 0 _] 'Fizz) ([_ _ 0] 'Buzz) ([n _ _] n))

Hello, Demo.

Hello, Proctor. http://www.proctor-it.com

@stevenproctor

steven.proctor@gmail.com

@fngeekery

http://www.functionalgeekery.com

@dfwerlang

http://www.meetup.com/DFW-Erlang-User-Group/

@planeterlang

http://www.planeterlang.com

http://www.proctor-it.comhttp://www.planeterlang.com