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

A "Hello World" style lightning talk I prepared for a Hello World of programming languages event at work. The goal was to give a rundown of languages we have been playing with and are interested in, and share an overview of the language.

The requirement was to give an overview of the language; where it's weaknesses might lie, as no language is perfect for everything; show FizzBuzz in the presentation to have a baseline, and show off an example of what makes it interesting, which included a demo of the Erlang VM's ability to do live code reloading.

Transcript

1. 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)
2. Hello, Erlang. Erlang and OTP was designed for building distributed, asynchronous, highly-concurrent, fault tolerant applications with high availability.
3. Hello, Erlang. Erlang and OTP was designed for building distributed, asynchronous, highly-concurrent, fault tolerant applications with high availability. #BuzzwordBingo
4. Hello, Telecom.
5. Hello, Telecom. • 100s of Thousands, if not Millions, of calls happen at the same time
6. Hello, Telecom. • 100s of Thousands, if not Millions, of calls happen at the same time • Your phone line has to always be available
7. 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
8. Hello, Déjà vu
9. Hello, Déjà vu • Sound Familiar?
10. Hello, Internet!
11. Hello, Failure.
12. Hello, Failure. • In the Real World things fail. Embrace it.
13. Hello, Failure. • In the Real World things fail. Embrace it. • “Let It Crash” philosophy
14. Hello, Failure. • In the Real World things fail. Embrace it. • “Let It Crash” philosophy • Immutability
15. Hello, Failure. • In the Real World things fail. Embrace it. • “Let It Crash” philosophy • Immutability • No Shared State
16. 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)
17. 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
18. 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
19. Hello, C10k Problem.
20. Hello, C10k Problem.
21. Hello, C10k Problem.
22. –Alan Kay I thought of objects being like biological cells and/or individual computers on a network, only able to communicate with messages […].2 Hello, OOP. 2. http://userpage.fu-berlin.de/~ram/pub/pub_jf47ht81Ht/doc_kay_oop_en
23. Hello, “Weaknesses”.
24. Hello, “Weaknesses”. • No strings as a data type
25. Hello, “Weaknesses”. • No strings as a data type • List of Integers or Binary types
26. 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
27. 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
28. 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;
29. 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.
30. 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?
31. 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
32. 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
33. Hello, FizzBuzz.
34. 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).
35. 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
36. 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))
37. Hello, Demo.
38. 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