merge(erlang-presentation): Merge at //presentations/erlang-2016 r/258

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diff --git a/presentations/erlang-2016/presentation.md b/presentations/erlang-2016/presentation.md
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+slidenumbers: true
+Erlang.
+======
+
+### Fault-tolerant, concurrent programming.
+
+---
+
+## A brief history of Erlang
+
+---
+
+![](https://www.ericsson.com/thinkingahead/the-networked-society-blog/wp-content/uploads/2014/09/bfW5FSr.jpg)
+
+
+^ Telefontornet in Stockholm, around 1890. Used until 1913. 
+
+---
+
+![](https://3.bp.blogspot.com/-UF7W9yTUO2g/VBqw-1HNTzI/AAAAAAAAPeg/KvsMbNSAcII/s1600/6835942484_1531372d8f_b.jpg)
+
+^ Telephones were operated manually at Switchboards. Anyone old enough to remember? I'm certainly not. 
+
+---
+
+![fit](https://russcam.github.io/fsharp-akka-talk/images/ericsson-301-AXD.png)
+
+^ Eventually we did that in software, and we got better at it over time. Ericsson AXD 301, first commercial Erlang switch. But lets take a step back.
+
+---
+
+## Phone switches must be ...
+
+Highly concurrent
+
+Fault-tolerant
+
+Distributed
+
+(Fast!)
+
+![right 150%](http://learnyousomeerlang.com/static/img/erlang-the-movie.png)
+
+---
+
+## ... and so is Erlang!
+
+---
+
+## Erlang as a whole:
+
+- Unique process model (actors!)
+- Built-in fault-tolerance & error handling
+- Distributed processes
+- Three parts!
+
+---
+
+## Part 1: Erlang, the language
+
+- Functional
+- Prolog-inspired syntax
+- Everything is immutable
+- *Extreme* pattern-matching
+
+---
+### Hello Joe
+
+```erlang
+hello_joe.
+```
+
+---
+### Hello Joe
+
+```erlang
+-module(hello1).
+-export([hello_joe/0]).
+
+hello_joe() ->
+    hello_joe.
+```
+
+---
+### Hello Joe
+
+```erlang
+-module(hello1).
+-export([hello_joe/0]).
+
+hello_joe() ->
+    hello_joe.
+    
+% 1> c(hello1).
+% {ok,hello1}
+% 2> hello1:hello_joe().
+% hello_joe
+```
+
+---
+### Hello Joe
+
+```erlang
+-module(hello2).
+-export([hello/1]).
+
+hello(Name) ->
+    io:format("Hello ~s!~n", [Name]).
+
+% 3> c(hello2).
+% {ok,hello2}
+% 4> hello2:hello("Joe").
+% Hello Joe!
+% ok
+```
+
+---
+
+## [fit] Hello ~~world~~ Joe is boring!
+## [fit] Lets do it with processes.
+
+---
+### Hello Server
+
+```erlang
+-module(hello_server).
+-export([start_server/0]).
+
+start_server() ->
+    spawn(fun() -> server() end).
+
+server() ->
+    receive
+        {greet, Name} ->
+            io:format("Hello ~s!~n", [Name]),
+            server()
+    end.
+```
+
+---
+
+## [fit] Some issues with that ...
+
+- What about unused messages?
+- What if the server crashes?
+
+---
+
+## [fit] Part 2: Open Telecom Platform
+
+### **It's called Erlang/OTP for a reason.**
+
+---
+
+# OTP: An Application Framework
+
+- Supervision - keep processes alive!
+
+- OTP Behaviours - common process patterns
+
+- Extensive standard library
+
+- Error handling, debuggers, testing, ...
+
+- Lots more!
+
+^ Standard library includes lots of things from simple network libraries over testing frameworks to cryptography, complete LDAP clients etc.
+
+---
+
+# Supervision
+
+![inline](http://erlang.org/doc/design_principles/sup6.gif)
+
+^ Supervision keeps processes alive, different restart behaviours, everything should be supervised to avoid "process" (and therefore memory) leaks
+
+---
+
+# OTP Behaviours
+
+* `gen_server`
+* `gen_statem` 
+* `gen_event`
+* `supervisor`
+
+^ gen = generic. explain server, explain statem, event = event handling with registered handlers, supervisor ...
+
+---
+
+`gen_server`
+
+---
+
+## [fit] Part 3: BEAM
+
+### Bogdan/Bjørn Erlang Abstract machine
+
+---
+
+## A VM for Erlang
+
+* Many were written, BEAM survived
+* Concurrent garbage-collection
+* Lower-level bytecode than JVM
+* Very open to new languages
+  (Elixir, LFE, Joxa, ...)
+
+---
+
+## What next?
+
+* Ole's talk, obviously!
+* Learn You Some Erlang!
+  www.learnyousomeerlang.com
+* Watch *Erlang the Movie*
+* (soon!) Join the Oslo BEAM meetup group
+
+---
+
+# [fit] Questions?
+
+`@tazjin`
diff --git a/presentations/erlang-2016/presentation.pdf b/presentations/erlang-2016/presentation.pdf
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index 0000000000..ec8d996704
--- /dev/null
+++ b/presentations/erlang-2016/presentation.pdf
Binary files differdiff --git a/presentations/erlang-2016/src/hello.erl b/presentations/erlang-2016/src/hello.erl
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index 0000000000..56404a0c5a
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+++ b/presentations/erlang-2016/src/hello.erl
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+-module(hello).
+-export([hello_joe/0]).
+
+hello_joe() ->
+    hello_joe.
diff --git a/presentations/erlang-2016/src/hello1.erl b/presentations/erlang-2016/src/hello1.erl
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index 0000000000..ca78261399
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+++ b/presentations/erlang-2016/src/hello1.erl
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+-module(hello1).
+-export([hello_joe/0]).
+
+hello_joe() ->
+    hello_joe.
diff --git a/presentations/erlang-2016/src/hello2.erl b/presentations/erlang-2016/src/hello2.erl
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index 0000000000..2d1f6c84c4
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+++ b/presentations/erlang-2016/src/hello2.erl
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+-module(hello2).
+-export([hello/1]).
+
+hello(Name) ->
+    io:format("Hey ~s!~n", [Name]).
+
+% 3> c(hello2).
+% {ok,hello2}
+% 4> hello2:hello("Joe").
+% Hello Joe!
+% ok
diff --git a/presentations/erlang-2016/src/hello_server.erl b/presentations/erlang-2016/src/hello_server.erl
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index 0000000000..01df14ac57
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+++ b/presentations/erlang-2016/src/hello_server.erl
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+-module(hello_server).
+-export([start_server/0, server/0]).
+
+start_server() ->
+    spawn(fun() -> server() end).
+
+server() ->
+    receive
+        {greet, Name} ->
+            io:format("Hello ~s!~n", [Name]),
+            hello_server:server()
+    end.
diff --git a/presentations/erlang-2016/src/hello_server2.erl b/presentations/erlang-2016/src/hello_server2.erl
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index 0000000000..24bb934ee5
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+++ b/presentations/erlang-2016/src/hello_server2.erl
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+-module(hello_server2).
+-behaviour(gen_server).
+-compile(export_all).
+
+%%% Start callback for supervisor
+start_link() ->
+    gen_server:start_link({local, ?MODULE}, ?MODULE, [], []).
+
+%%% gen_server callbacks
+
+init([]) ->
+    {ok, sets:new()}.
+
+handle_call({greet, Name}, _From, State) ->
+    io:format("Hello ~s!~n", [Name]),
+    NewState = sets:add_element(Name, State),
+    {reply, ok, NewState};
+
+handle_call({bye, Name}, _From, State) ->
+    io:format("Goodbye ~s!~n", [Name]),
+    NewState = sets:del_element(Name, State),
+    {reply, ok, NewState}.
+
+terminate(normal, State) ->
+    [io:format("Goodbye ~s!~n", [Name]) || Name <- State],
+    ok.
+
+%%% Unused gen_server callbacks
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+handle_cast(_Request, State) ->
+    {noreply, State}.
diff --git a/presentations/erlang-2016/src/hello_sup.erl b/presentations/erlang-2016/src/hello_sup.erl
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+-module(hello_sup).
+-behaviour(supervisor).
+-export([start_link/0, init/1]).
+
+%%% Module API
+
+start_link() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+%%% Supervisor callbacks
+
+init([]) ->
+    Children = [hello_spec()],
+    {ok, { {one_for_one, 5, 10}, Children}}.
+
+%%% Private
+
+hello_spec() ->
+    #{id       => hello_server2,
+      start    => {hello_server2, start_link, []},
+      restart  => permanent,
+      shutdown => 5000,
+      type     => worker,
+      module   => [hello_server2]}.