1. Erlang

2. What is it?
created by Joe Armstrong in 1986 at Ericcsson Telecom
based on Prolog
functional language
dynamicly typed

3. Erlang is...
reliable
high concurrent (no threads. light processes)
modular

4. Where is it used?
RabbitMQ (France telecom)
CouchDB
Facebook Chat
GitHub (egitd)
SimpleDB (AWS)

5. Types

6. Variables
Var = 2.
Var.
%=> 2
Var = 3. % this throws an error!

7. atoms
this_is_atom

8. Lists
[1,2,3,4]

9. Tuples
{a, 2,"d"}.
{ company,
{name, "Applicake",
{address, "Krakow"}}
}.

10. Matching
Company = {company,
{name, "Applicake"},
{address, "Krakow"}
}.
{company, {name, Name,
{address, Address}}} = Company.
Name %=> "Applicake"
Address %=> "Krakow"

11. Matching
[Head | Tail] = [1,2,3,4].
Head. %=> 1
Tail. %=> [2,3,4]

12. Matching
[One, Two | Rest] = [1,2,3,4].
One. %=> 1
Two. %=> 2
Rest.%=> [3,4]

13. functions
-module(mirror_function).
-export([mirror/1]).
mirror(Argument) -> Argument.

14. functions
-module(matching_function).
-export([number/1]).
number(one) -> 1;
number(two) -> 2;
number(three) -> 3.

15. functions
Numbers = [1,2,3,4].
lists:map(fun(X) -> X+1 end, Numbers).
%=> [2,3,4,5]

16. functions
map(F, [H|T]) -> [F(H) | map(F, T)];
map(F, []) -> [].

17. Control structures
case...
case Animal of
"dog" -> underdoga;
"cat" -> thundercat
_ -> something_else
end.

18. Control structures
if...
if
X > 0 -> positive;
X < 0 -> negative;
true -> zero
end.

19. Processes

20. Processes
Pid = spawn(fun module_name:function_name/0).
Pid ! "message".

21. Processes
fuction_name() ->
receive
"message" ->
io::format("Hi!"),
function_name();
_ ->
io::format("Whatever..."),
function_name()
end.