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add .formatter.exs + format

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This commit is contained in:
Martino Visintin
2018-05-22 21:46:54 +01:00
parent 08c90ce0d8
commit b07df7c780
52 changed files with 332 additions and 264 deletions
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2
lib/koans/01_equalities.ex
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@@ -1,7 +1,7 @@
defmodule Equalities do
use Koans
@intro """
@intro """
Welcome to the Elixir koans.
Let these be your first humble steps towards learning a new language.

6
lib/koans/04_atoms.ex
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@@ -11,12 +11,12 @@ defmodule Atoms do
koan "It is surprising to find out that booleans are atoms" do
assert is_atom(true) == ___
assert is_boolean(false) == ___
assert :true == ___
assert :false == ___
assert true == ___
assert false == ___
end
koan "Like booleans, the nil value is also an atom" do
assert is_atom(nil) == ___
assert :nil == ___
assert nil == ___
end
end

6
lib/koans/08_maps.ex
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@@ -6,13 +6,11 @@ defmodule Maps do
@person %{
first_name: "Jon",
last_name: "Snow",
age: 27,
age: 27
}
koan "Maps represent structured data, like a person" do
assert @person == %{first_name: ___,
last_name: "Snow",
age: 27 }
assert @person == %{first_name: ___, last_name: "Snow", age: 27}
end
koan "Fetching a value returns a tuple with ok when it exists" do

2
lib/koans/10_structs.ex
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@@ -49,7 +49,7 @@ defmodule Structs do
koan "Use the update_in macro to modify a nested value" do
airline = %Airline{plane: %Plane{maker: :boeing, passengers: 200}}
assert update_in(airline.plane.passengers, fn(x) -> (x + 2) end) == ___
assert update_in(airline.plane.passengers, fn x -> x + 2 end) == ___
end
koan "Use the put_in macro with atoms to replace a nested value in a non-struct" do

4
lib/koans/11_sigils.ex
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@@ -17,7 +17,7 @@ defmodule Sigils do
end
koan "The lowercase ~s sigil supports string interpolation" do
assert ~s[1 + 1 = #{1+1}] == ___
assert ~s[1 + 1 = #{1 + 1}] == ___
end
koan "The ~S sigil is similar to ~s but doesn't do interpolation" do
@@ -29,7 +29,7 @@ defmodule Sigils do
end
koan "The ~w sigil also allows interpolation" do
assert ~w(Hello 1#{1+1}3) == ___
assert ~w(Hello 1#{1 + 1}3) == ___
end
koan "The ~W sigil behaves to ~w as ~S behaves to ~s" do

37
lib/koans/12_pattern_matching.ex
View File

@@ -41,7 +41,7 @@ defmodule PatternMatching do
koan "Lists must match exactly" do
assert_raise ___, fn ->
[a, b] = [1,2,3]
[a, b] = [1, 2, 3]
end
end
@@ -71,9 +71,9 @@ defmodule PatternMatching do
koan "And they will only run the code that matches the argument" do
name = fn
("duck") -> "Donald"
("mouse") -> "Mickey"
(_other) -> "I need a name!"
"duck" -> "Donald"
"mouse" -> "Mickey"
_other -> "I need a name!"
end
assert name.("mouse") == ___
@@ -84,10 +84,11 @@ defmodule PatternMatching do
koan "Errors are shaped differently than successful results" do
dog = %{type: "dog"}
result = case Map.fetch(dog, :type) do
{:ok, value} -> value
:error -> "not present"
end
result =
case Map.fetch(dog, :type) do
{:ok, value} -> value
:error -> "not present"
end
assert result == ___
end
@@ -133,10 +134,11 @@ defmodule PatternMatching do
pinned_variable = 1
example = fn
(^pinned_variable) -> "The number One"
(2) -> "The number Two"
(number) -> "The number #{number}"
^pinned_variable -> "The number One"
2 -> "The number Two"
number -> "The number #{number}"
end
assert example.(1) == ___
assert example.(2) == ___
assert example.(3) == ___
@@ -144,17 +146,20 @@ defmodule PatternMatching do
koan "Pinning works anywhere one would match, including 'case'" do
pinned_variable = 1
result = case 1 do
^pinned_variable -> "same"
other -> "different #{other}"
end
result =
case 1 do
^pinned_variable -> "same"
other -> "different #{other}"
end
assert result == ___
end
koan "Trying to rebind a pinned variable will result in an error" do
a = 1
assert_raise MatchError, fn() ->
assert_raise MatchError, fn ->
^a = ___
end
end

22
lib/koans/13_functions.ex
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@@ -12,6 +12,7 @@ defmodule Functions do
end
def multiply(a, b), do: a * b
koan "Single line functions are cool, but mind the comma and the colon!" do
assert 6 == multiply(2, ___)
end
@@ -41,8 +42,8 @@ defmodule Functions do
assert sum_up(1) == ___
end
def bigger(a,b) when a > b, do: "#{a} is bigger than #{b}"
def bigger(a,b) when a <= b, do: "#{a} is not bigger than #{b}"
def bigger(a, b) when a > b, do: "#{a} is bigger than #{b}"
def bigger(a, b) when a <= b, do: "#{a} is not bigger than #{b}"
koan "Intricate guards are possible, but be mindful of the reader" do
assert bigger(10, 5) == ___
@@ -58,13 +59,13 @@ defmodule Functions do
end
koan "Little anonymous functions are common, and called with a dot" do
multiply = fn (a,b) -> a * b end
assert multiply.(2,3) == ___
multiply = fn a, b -> a * b end
assert multiply.(2, 3) == ___
end
koan "You can even go shorter, by using capture syntax `&()` and positional arguments" do
multiply = &(&1 * &2)
assert multiply.(2,3) == ___
assert multiply.(2, 3) == ___
end
koan "Prefix a string with & to build a simple anonymous greet function" do
@@ -77,7 +78,7 @@ defmodule Functions do
assert three_times.("foo") == ___
end
def times_five_and_then(number, fun), do: fun.(number*5)
def times_five_and_then(number, fun), do: fun.(number * 5)
def square(number), do: number * number
koan "You can pass functions around as arguments. Place an '&' before the name and state the arity" do
@@ -90,10 +91,11 @@ defmodule Functions do
end
koan "The result of a function can be piped into another function as its first argument" do
result = "full-name"
|> String.split("-")
|> Enum.map(&String.capitalize/1)
|> Enum.join(" ")
result =
"full-name"
|> String.split("-")
|> Enum.map(&String.capitalize/1)
|> Enum.join(" ")
assert result == ___
end

6
lib/koans/14_enums.ex
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@@ -12,12 +12,14 @@ defmodule Enums do
end
def less_than_five?(n), do: n < 5
koan "Elements can have a lot in common" do
assert Enum.all?([1, 2, 3], &less_than_five?/1) == ___
assert Enum.all?([4, 6, 8], &less_than_five?/1) == ___
end
def even?(n), do: rem(n, 2) == 0
koan "Sometimes you just want to know if there are any elements fulfilling a condition" do
assert Enum.any?([1, 2, 3], &even?/1) == ___
assert Enum.any?([1, 3, 5], &even?/1) == ___
@@ -30,6 +32,7 @@ defmodule Enums do
end
def multiply_by_ten(n), do: 10 * n
koan "Map converts each element of a list by running some function with it" do
assert Enum.map([1, 2, 3], &multiply_by_ten/1) == ___
end
@@ -67,6 +70,7 @@ defmodule Enums do
end
def divisible_by_five?(n), do: rem(n, 5) == 0
koan "...but you don't quite find it..." do
assert Enum.find([1, 2, 3], &divisible_by_five?/1) == ___
end
@@ -76,6 +80,6 @@ defmodule Enums do
end
koan "Collapse an entire list of elements down to a single one by repeating a function." do
assert Enum.reduce([1, 2, 3], 0, fn(element, accumulator) -> element + accumulator end) == ___
assert Enum.reduce([1, 2, 3], 0, fn element, accumulator -> element + accumulator end) == ___
end
end

70
lib/koans/15_processes.ex
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@@ -18,9 +18,11 @@ defmodule Processes do
end
koan "New processes are spawned functions" do
value = spawn(fn -> receive do
end
end)
value =
spawn(fn ->
receive do
end
end)
assert is_pid(value) == ___
end
@@ -39,7 +41,7 @@ defmodule Processes do
end
koan "Processes can send and receive messages" do
send self(), "hola!"
send(self(), "hola!")
receive do
msg -> assert msg == ___
@@ -58,8 +60,8 @@ defmodule Processes do
end
koan "Received messages are queued, first in first out" do
send self(), "hola!"
send self(), "como se llama?"
send(self(), "hola!")
send(self(), "como se llama?")
assert_receive ___
assert_receive ___
@@ -68,20 +70,20 @@ defmodule Processes do
koan "A common pattern is to include the sender in the message, so that it can reply" do
greeter = fn ->
receive do
{:hello, sender} -> send sender, :how_are_you?
{:hello, sender} -> send(sender, :how_are_you?)
end
end
pid = spawn(greeter)
send pid, {:hello, self()}
send(pid, {:hello, self()})
assert_receive ___
end
def yelling_echo_loop do
receive do
{caller, value} ->
send caller, String.upcase(value)
send(caller, String.upcase(value))
yelling_echo_loop()
end
end
@@ -89,18 +91,19 @@ defmodule Processes do
koan "Use tail recursion to receive multiple messages" do
pid = spawn_link(&yelling_echo_loop/0)
send pid, {self(), "o"}
send(pid, {self(), "o"})
assert_receive ___
send pid, {self(), "hai"}
send(pid, {self(), "hai"})
assert_receive ___
end
def state(value) do
receive do
{caller, :get} ->
send caller, value
send(caller, value)
state(value)
{caller, :set, new_value} ->
state(new_value)
end
@@ -108,38 +111,45 @@ defmodule Processes do
koan "Processes can be used to hold state" do
initial_state = "foo"
pid = spawn(fn ->
state(initial_state)
end)
send pid, {self(), :get}
pid =
spawn(fn ->
state(initial_state)
end)
send(pid, {self(), :get})
assert_receive ___
send pid, {self(), :set, "bar"}
send pid, {self(), :get}
send(pid, {self(), :set, "bar"})
send(pid, {self(), :get})
assert_receive ___
end
koan "Waiting for a message can get boring" do
parent = self()
spawn(fn -> receive do
after
5 -> send parent, {:waited_too_long, "I am impatient"}
end
end)
spawn(fn ->
receive do
after
5 -> send(parent, {:waited_too_long, "I am impatient"})
end
end)
assert_receive ___
end
koan "Trapping will allow you to react to someone terminating the process" do
parent = self()
pid = spawn(fn ->
Process.flag(:trap_exit, true)
send parent, :ready
receive do
{:EXIT, _pid, reason} -> send parent, {:exited, reason}
end
end)
pid =
spawn(fn ->
Process.flag(:trap_exit, true)
send(parent, :ready)
receive do
{:EXIT, _pid, reason} -> send(parent, {:exited, reason})
end
end)
receive do
:ready -> true

30
lib/koans/16_tasks.ex
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@@ -10,23 +10,26 @@ defmodule Tasks do
end
koan "If you don't need a result, use start_link/1" do
{result, _pid} = Task.start_link(fn -> 1+1 end)
{result, _pid} = Task.start_link(fn -> 1 + 1 end)
assert result == ___
end
koan "Yield returns nil if the task isn't done yet" do
handle = Task.async(fn ->
:timer.sleep(100)
3 * 3
end)
handle =
Task.async(fn ->
:timer.sleep(100)
3 * 3
end)
assert Task.yield(handle, 10) == ___
end
koan "Tasks can be aborted with shutdown" do
handle = Task.async(fn ->
:timer.sleep(100)
3 * 3
end)
handle =
Task.async(fn ->
:timer.sleep(100)
3 * 3
end)
%Task{pid: pid} = handle
Task.shutdown(handle)
@@ -41,10 +44,11 @@ defmodule Tasks do
end
koan "You can yield to multiple tasks at once and extract the results" do
squares = [1, 2, 3, 4]
|> Enum.map(fn(number) -> Task.async(fn -> number * number end) end)
|> Task.yield_many(100)
|> Enum.map(fn({_task,{:ok, result}}) -> result end)
squares =
[1, 2, 3, 4]
|> Enum.map(fn number -> Task.async(fn -> number * number end) end)
|> Task.yield_many(100)
|> Enum.map(fn {_task, {:ok, result}} -> result end)
assert squares == ___
end

24
lib/koans/17_agents.ex
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@@ -5,36 +5,38 @@ defmodule Agents do
koan "Agents maintain state, so you can ask them about it" do
{:ok, pid} = Agent.start_link(fn -> "Hi there" end)
assert Agent.get(pid, &(&1)) == ___
assert Agent.get(pid, & &1) == ___
end
koan "Agents may also be named so that you don't have to keep the pid around" do
Agent.start_link(fn -> "Why hello" end, name: AgentSmith)
assert Agent.get(AgentSmith, &(&1)) == ___
assert Agent.get(AgentSmith, & &1) == ___
end
koan "Update to update the state" do
Agent.start_link(fn() -> "Hi there" end, name: __MODULE__)
Agent.start_link(fn -> "Hi there" end, name: __MODULE__)
Agent.update(__MODULE__, fn(old) ->
Agent.update(__MODULE__, fn old ->
String.upcase(old)
end)
assert Agent.get(__MODULE__, &(&1)) == ___
assert Agent.get(__MODULE__, & &1) == ___
end
koan "Use get_and_update when you need to read and change a value in one go" do
Agent.start_link(fn() -> ["Milk"] end, name: __MODULE__)
Agent.start_link(fn -> ["Milk"] end, name: __MODULE__)
old_list = Agent.get_and_update(__MODULE__, fn(old) ->
{old, ["Bread" | old]}
end)
old_list =
Agent.get_and_update(__MODULE__, fn old ->
{old, ["Bread" | old]}
end)
assert old_list == ___
assert Agent.get(__MODULE__, &(&1)) == ___
assert Agent.get(__MODULE__, & &1) == ___
end
koan "Somebody has to switch off the light at the end of the day" do
{:ok, pid} = Agent.start_link(fn() -> ["Milk"] end, name: __MODULE__)
{:ok, pid} = Agent.start_link(fn -> ["Milk"] end, name: __MODULE__)
Agent.stop(__MODULE__)

6
lib/koans/18_genservers.ex
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@@ -46,7 +46,7 @@ defmodule GenServers do
# GenServer implementation
def handle_call(:get_password, _from, current_password) do
{:reply, current_password, current_password}
{:reply, current_password, current_password}
end
def handle_call(:get_manufacturer, _from, current_state) do
@@ -73,6 +73,7 @@ defmodule GenServers do
case password do
password when password === current_password ->
{:reply, {:ok, "Laptop unlocked!"}, current_password}
_ ->
{:reply, {:error, "Incorrect password!"}, current_password}
end
@@ -82,6 +83,7 @@ defmodule GenServers do
case old_password do
old_password when old_password == current_password ->
{:noreply, new_password}
_ ->
{:noreply, current_password}
end
@@ -147,7 +149,7 @@ defmodule GenServers do
{_, response} = Laptop.unlock("EL!73")
assert response == ___
{_, response} = Laptop.owner_name
{_, response} = Laptop.owner_name()
assert response == ___
end
end

8
lib/koans/19_protocols.ex
View File

@@ -3,7 +3,7 @@ defmodule Protocols do
@intro "Want to follow the rules? Adhere to the protocol!"
defprotocol School, do: def enroll(person)
defprotocol(School, do: def(enroll(person)))
defimpl School, for: Any do
def enroll(_) do
@@ -16,9 +16,9 @@ defmodule Protocols do
defstruct name: ""
end
defmodule Musician, do: defstruct name: "", instrument: ""
defmodule Dancer, do: defstruct name: "", dance_style: ""
defmodule Baker, do: defstruct name: ""
defmodule(Musician, do: defstruct(name: "", instrument: ""))
defmodule(Dancer, do: defstruct(name: "", dance_style: ""))
defmodule(Baker, do: defstruct(name: ""))
defimpl School, for: Musician do
def enroll(musician) do