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<!DOCTYPE html>

<head>

<title>Erlang/Elixir Syntax: A Crash Course - Elixir</title>

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</div>

<h1 id="erlangelixir-syntax-a-crash-course">Erlang/Elixir Syntax: A Crash Course</h1>

This is a quick introduction to the Elixir syntax for Erlang developers and vice-versa. It is the absolute minimum amount of knowledge you need in order to understand Elixir/Erlang code, support interoperability, read the docs, sample code, etc.

<h2 id="running-code">Running code</h2>

<h3 id="erlang">Erlang</h3>

The fastest way to run some code is to launch the Erlang shell – <code class="highlighter-rouge">erl</code>. Many code snippets on this page can be pasted directly into the shell. However, when you want to define a named function, Erlang expects it to be inside of a module, and modules have to be compiled. Here’s a skeleton for a module:

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>% module_name.erl

-module(module_name). % you may use some other name

-compile(export_all).

hello() ->

io:format("~s~n", ["Hello world!"]).

</code></pre>

</div>

Add your functions to it, save it to disk, run <code class="highlighter-rouge">erl</code> from the same directory and execute the <code class="highlighter-rouge">compile</code> command:

<div class="language-erl highlighter-rouge"><pre class="highlight"><code>Eshell V5.9 (abort with ^G)

1> c(module_name).

ok

1> module_name:hello().

Hello world!

ok

</code></pre>

</div>

You may keep the shell running while you’re editing the file. Just don’t forget to execute <code class="highlighter-rouge">c(module_name)</code> to load the latest changes. Note that the filename has to be the same as the one declared in the <code class="highlighter-rouge">-module()</code> directive, plus an extension <code class="highlighter-rouge">.erl</code>.

<h3 id="elixir">Elixir</h3>

Elixir too has an interactive shell called <code class="highlighter-rouge">iex</code>. Compiling Elixir code can be done with <code class="highlighter-rouge">elixirc</code> (which is similar to Erlang’s <code class="highlighter-rouge">erlc</code>). Elixir also provides an executable named <code class="highlighter-rouge">elixir</code> to run Elixir code. The module defined above can be written in Elixir as:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code># module_name.ex

defmodule ModuleName do

def hello do

IO.puts "Hello World"

end

</code></pre>

</div>

And compiled from <code class="highlighter-rouge">iex</code>:

<pre><code class="language-iex">Interactive Elixir

iex> c("module_name.ex")

[ModuleName]

iex> ModuleName.hello

Hello world!

:ok

</code></pre>

However notice that in Elixir you don’t need to create a file only to create a new module, Elixir modules can be defined directly in the shell:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>defmodule MyModule do

def hello do

IO.puts "Another Hello"

end

</code></pre>

</div>

<h2 id="notable-differences">Notable differences</h2>

This section goes over some of the syntactic differences between the two languages.

<h3 id="operator-names">Operator names</h3>

Some operators are spelled differently.

<table>

<thead>

<tr>

<th>Erlang</th>

<th>Elixir</th>

<th>Meaning</th>

</tr>

</thead>

<tbody>

<tr>

<td>NOT AVAILABLE</td>

<td>Logical ‘and’, evaluates both arguments</td>

</tr>

<tr>

<td>andalso</td>

<td>Logical ‘and’, short-circuits</td>

</tr>

<tr>

<td>NOT AVAILABLE</td>

<td>Logical ‘or’, evaluates both arguments</td>

</tr>

<tr>

<td>orelse</td>

<td>Logical ‘or’, short-circuits</td>

</tr>

<tr>

<td>A match operator</td>

</tr>

<tr>

<td>A negative match</td>

</tr>

<tr>

<td>Not equals</td>

</tr>

<tr>

<td>Less than or equals</td>

</tr>

</tbody>

</table>

<h3 id="delimiters">Delimiters</h3>

Erlang expressions are terminated with a dot <code class="highlighter-rouge">.</code> and comma <code class="highlighter-rouge">,</code> is used to evaluate multiple expressions within one context (in a function definition, for instance). In Elixir, expressions are delimited by a line break or a semicolon <code class="highlighter-rouge">;</code>.

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>X = 2, Y = 3.

X + Y.

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>x = 2; y = 3

x + y

</code></pre>

</div>

<h3 id="variable-names">Variable names</h3>

Variables in Erlang can only be assigned once. The Erlang shell provides a special command <code class="highlighter-rouge">f</code> that allows you to erase the binding of a variable or all variables at once.

Elixir allows you to assign to a variable more than once. If you want to match against the value of a previously assigned variable, you should use <code class="highlighter-rouge">^</code>:

Erlang

1> X = 10.

10

2> X = X + 1.

** exception error: no match of right hand side value 11

3> X1 = X + 1.

11

4> f(X).

ok

5> X = X1 * X1.

121

6> f().

ok

7> X.

* 1: variable 'X' is unbound

8> X1.

* 1: variable 'X1' is unbound

</code></pre>

</div>

Elixir

<pre><code class="language-iex">iex> a = 1

iex> a = 2

iex> ^a = 3

** (MatchError) no match of right hand side value: 3

</code></pre>

<h3 id="calling-functions">Calling functions</h3>

Invoking a function from a module uses different syntax. In Erlang, you would write

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>lists:last([1, 2]).

</code></pre>

</div>

to invoke the <code class="highlighter-rouge">last</code> function from the <code class="highlighter-rouge">List</code> module. In Elixir, use the dot <code class="highlighter-rouge">.</code> in place of the colon <code class="highlighter-rouge">:</code>

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>List.last([1, 2])

</code></pre>

</div>

Note. Since Erlang modules are represented by atoms, you may invoke Erlang functions in Elixir as follows:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>:lists.sort([3, 2, 1])

</code></pre>

</div>

All of the Erlang built-ins reside in the <code class="highlighter-rouge">:erlang</code> module.

<h2 id="data-types">Data types</h2>

Erlang and Elixir have the same data types for the most part, but there are a number of differences.

<h3 id="atoms">Atoms</h3>

In Erlang, an <code class="highlighter-rouge">atom</code> is any identifier that starts with a lowercase letter, e.g. <code class="highlighter-rouge">ok</code>, <code class="highlighter-rouge">tuple</code>, <code class="highlighter-rouge">donut</code>. Identifiers that start with a capital letter are always treated as variable names. Elixir, on the other hand, uses the former for naming variables, and the latter are treated as atom aliases. Atoms in Elixir always start with a colon <code class="highlighter-rouge">:</code>.

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>im_an_atom.

me_too.

Im_a_var.

X = 10.

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>:im_an_atom

:me_too

im_a_var

x = 10

Module # this is called an atom alias; it expands to :'Elixir.Module'

</code></pre>

</div>

It is also possible to create atoms that start with a character other than a lowercase letter. The syntax is different between the two languages:

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>is_atom(ok). %=> true

is_atom('0_ok'). %=> true

is_atom('Multiple words'). %=> true

is_atom(''). %=> true

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>is_atom :ok #=> true

is_atom :'ok' #=> true

is_atom Ok #=> true

is_atom :"Multiple words" #=> true

is_atom :"" #=> true

</code></pre>

</div>

<h3 id="tuples">Tuples</h3>

The syntax for tuples is the same in both languages, but the APIs are different. Elixir attempts to normalize Erlang libraries in a way that:

<ol>

<li>The <code class="highlighter-rouge">subject</code> of the function is always the first argument.</li>

<li>All data structures functions employ zero-based access.</li>

</ol>

That said, Elixir does not import the default <code class="highlighter-rouge">element</code> and <code class="highlighter-rouge">setelement</code> functions, but instead provides <code class="highlighter-rouge">elem</code> and <code class="highlighter-rouge">put_elem</code>:

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>element(1, {a, b, c}). %=> a

setelement(1, {a, b, c}, d). %=> {d, b, c}

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>elem({:a, :b, :c}, 0) #=> :a

put_elem({:a, :b, :c}, 0, :d) #=> {:d, :b, :c}

</code></pre>

</div>

<h3 id="lists-and-binaries">Lists and binaries</h3>

Elixir has a shortcut syntax for binaries:

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>is_list('Hello'). %=> false

is_list("Hello"). %=> true

is_binary(<<"Hello">>). %=> true

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>is_list 'Hello' #=> true

is_binary "Hello" #=> true

is_binary <<"Hello">> #=> true

<<"Hello">> === "Hello" #=> true

</code></pre>

</div>

In Elixir, the word string means a UTF-8 binary and there is a <code class="highlighter-rouge">String</code> module that works on such data. Elixir also expects your source files to be UTF-8 encoded. On the other hand, string in Erlang refers to char lists and there is a <code class="highlighter-rouge">:string</code> module that works mostly with both char lists and UTF-8 encoded binaries.

Elixir also supports multiline strings (also called heredocs):

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>is_binary """

This is a binary

spanning several

lines.

"""

#=> true

</code></pre>

</div>

<h3 id="keyword-list">Keyword list</h3>

Elixir offers a literal syntax for creating a list of two-item tuples where the first item in the tuple is an atom and calls them keyword lists:

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>Proplist = [{another_key, 20}, {key, 10}].

proplists:get_value(another_key, Proplist).

%=> 20

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>kw = [another_key: 20, key: 10]

kw[:another_key]

#=> 20

</code></pre>

</div>

Erlang R17 introduced maps, a key-value store, with no ordering. Keys and values can be any term. Creating, updating and matching maps in both languages is shown below:

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>Map = #{key => 0}.

Updated = Map#{key := 1}.

#{key := Value} = Updated.

Value =:= 1.

%=> true

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>map = %{:key => 0}

map = %{map | :key => 1}

%{:key => value} = map

value === 1

#=> true

</code></pre>

</div>

If the keys are all atoms, Elixir allows developers to use <code class="highlighter-rouge">key: 0</code> for defining the map as well as using <code class="highlighter-rouge">.key</code> for accessing fields:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>map = %{key: 0}

map = %{map | key: 1}

map.key === 1

</code></pre>

</div>

<h3 id="regular-expressions">Regular expressions</h3>

Elixir supports a literal syntax for regular expressions. Such syntax allows regexes to be compiled at compilation time instead of runtime and does not require you to double escape special regex characters:

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>{ ok, Pattern } = re:compile("abc\\s").

re:run("abc ", Pattern).

%=> { match, ["abc "] }

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>Regex.run ~r/abc\s/, "abc "

#=> ["abc "]

</code></pre>

</div>

Regexes are also supported in heredocs, which is convenient when defining multiline regexes:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>Regex.regex? ~r"""

This is a regex

spanning several

lines.

"""

#=> true

</code></pre>

</div>

<h2 id="modules">Modules</h2>

Each Erlang module lives in its own file which has the following structure:

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>-module(hello_module).

-export([some_fun/0, some_fun/1]).

% A "Hello world" function

some_fun() ->

io:format('~s~n', ['Hello world!']).

% This one works only with lists

some_fun(List) when is_list(List) ->

% Non-exported functions are private

priv() ->

secret_info.

</code></pre>

</div>

Here we create a module named <code class="highlighter-rouge">hello_module</code>. In it we define three functions, the first two are made available for other modules to call via the <code class="highlighter-rouge">export</code> directive at the top. It contains a list of functions, each of which is written in the format <code class="highlighter-rouge"><function name>/<arity></code>. Arity stands for the number of arguments.

An Elixir equivalent to the Erlang above:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>defmodule HelloModule do

# A "Hello world" function

def some_fun do

IO.puts "Hello world!"

end

# This one works only with lists

def some_fun(list) when is_list(list) do

IO.inspect list

end

# A private function

defp priv do

:secret_info

end

</code></pre>

</div>

In Elixir, it is also possible to have multiple modules in one file, as well as nested modules:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>defmodule HelloModule do

defmodule Utils do

def util do

IO.puts "Utilize"

end

defp priv do

:cant_touch_this

end

def dummy do

:ok

end

defmodule ByeModule do

end

HelloModule.dummy

#=> :ok

HelloModule.Utils.util

#=> "Utilize"

HelloModule.Utils.priv

#=> ** (UndefinedFunctionError) undefined function: HelloModule.Utils.priv/0

</code></pre>

</div>

<h2 id="function-syntax">Function syntax</h2>

<a href="http://learnyousomeerlang.com/syntax-in-functions">This chapter</a> from the Erlang book provides a detailed description of pattern matching and function syntax in Erlang. Here, I’m briefly covering the main points and provide sample code both in Erlang and Elixir.

<h3 id="pattern-matching">Pattern matching</h3>

Pattern matching in Elixir is based on Erlang’s implementation and in general is very similar:

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>loop_through([H | T]) ->

io:format('~p~n', [H]),

loop_through(T);

loop_through([]) ->

ok.

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>def loop_through([h | t]) do

IO.inspect h

loop_through t

end

def loop_through([]) do

:ok

end

</code></pre>

</div>

When defining a function with the same name multiple times, each such definition is called a clause. In Erlang, clauses always go side by side and are separated by a semicolon <code class="highlighter-rouge">;</code>. The last clause is terminated by a dot <code class="highlighter-rouge">.</code>.

Elixir doesn’t require punctuation to separate clauses, but they must be grouped together.

<h3 id="identifying-functions">Identifying functions</h3>

In both Erlang and Elixir, a function is not identified only by its name, but by its name and arity. In both examples below, we are defining four different functions (all named <code class="highlighter-rouge">sum</code>, but with different arity):

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>sum() -> 0.

sum(A) -> A.

sum(A, B, C) -> A + B + C.

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>def sum, do: 0

def sum(a), do: a

def sum(a, b, c), do: a + b + c

</code></pre>

</div>

Guard expressions provide a concise way to define functions that accept a limited set of values based on some condition.

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>sum(A, B) when is_integer(A), is_integer(B) ->

A + B;

sum(A, B) when is_list(A), is_list(B) ->

A ++ B;

sum(A, B) when is_binary(A), is_binary(B) ->

<<A/binary, B/binary>>.

sum(1, 2).

%=> 3

sum([1], [2]).

%=> [1, 2]

sum("a", "b").

%=> "ab"

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>def sum(a, b) when is_integer(a) and is_integer(b) do

a + b

end

def sum(a, b) when is_list(a) and is_list(b) do

a ++ b

end

def sum(a, b) when is_binary(a) and is_binary(b) do

a <> b

end

sum 1, 2

#=> 3

sum [1], [2]

#=> [1, 2]

sum "a", "b"

#=> "ab"

</code></pre>

</div>

<h3 id="default-values">Default values</h3>

In addition, Elixir allows for default values for arguments, whereas Erlang does not.

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>def mul_by(x, n \\ 2) do

x * n

end

mul_by 4, 3 #=> 12

mul_by 4 #=> 8

</code></pre>

</div>

<h3 id="anonymous-functions">Anonymous functions</h3>

Anonymous functions are defined in the following way:

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>Sum = fun(A, B) -> A + B end.

Sum(4, 3).

%=> 7

Square = fun(X) -> X * X end.

lists:map(Square, [1, 2, 3, 4]).

%=> [1, 4, 9, 16]

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>sum = fn(a, b) -> a + b end

sum.(4, 3)

#=> 7

square = fn(x) -> x * x end

Enum.map [1, 2, 3, 4], square

#=> [1, 4, 9, 16]

</code></pre>

</div>

It is possible to use pattern matching when defining anonymous functions, too.

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>F = fun(Tuple = {a, b}) ->

io:format("All your ~p are belong to us~n", [Tuple]);

([]) ->

"Empty"

end.

F([]).

%=> "Empty"

F({a, b}).

%=> "All your {a, b} are belong to us"

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>f = fn

{:a, :b} = tuple ->

IO.puts "All your #{inspect tuple} are belong to us"

[] ->

"Empty"

end

f.([])

#=> "Empty"

f.({:a, :b})

#=> "All your {:a, :b} are belong to us"

</code></pre>

</div>

<h3 id="first-class-functions">First-class functions</h3>

Anonymous functions are first-class values, so they can be passed as arguments to other functions and also can serve as a return value. There is a special syntax to allow named functions be treated in the same manner.

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>% math.erl

-module(math).

-export([square/1]).

square(X) -> X * X.

</code></pre>

</div>

1> c(math).

{ok,math}

2> lists:map(fun math:square/1, [1, 2, 3]).

[1,4,9]

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>defmodule Math do

def square(x) do

x * x

end

Enum.map [1, 2, 3], &Math.square/1

#=> [1, 4, 9]

</code></pre>

</div>

<h3 id="partials-and-function-captures-in-elixir">Partials and function captures in Elixir</h3>

Elixir supports partial application of functions which can be used to define anonymous functions in a concise way:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>Enum.map [1, 2, 3, 4], &(&1 * 2)

#=> [2, 4, 6, 8]

List.foldl [1, 2, 3, 4], 0, &(&1 + &2)

#=> 10

</code></pre>

</div>

We use the same <code class="highlighter-rouge">&</code> operator to capture a function, allowing us to pass named functions as arguments.

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>defmodule Math do

def square(x) do

x * x

end

Enum.map [1, 2, 3], &Math.square/1

#=> [1, 4, 9]

</code></pre>

</div>

The above would be equivalent to Erlang’s <code class="highlighter-rouge">fun math:square/1</code>.

<h2 id="control-flow">Control flow</h2>

The constructs <code class="highlighter-rouge">if</code> and <code class="highlighter-rouge">case</code> are actually expressions in both Erlang and Elixir, but may be used for control flow as in imperative languages.

The <code class="highlighter-rouge">case</code> construct provides control flow based purely on pattern matching.

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>case {X, Y} of

{a, b} -> ok;

{b, c} -> good;

Else -> Else

end

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>case {x, y} do

{:a, :b} -> :ok

{:b, :c} -> :good

other -> other

end

</code></pre>

</div>

Erlang

if X > 10 ->

greater_than_ten;

X < 10, X > 0 ->

less_than_ten_positive;

X < 0; X =:= 0 ->

zero_or_negative;

true ->

exactly_ten

end

end.

Test_fun(11).

%=> greater_than_ten

Test_fun(-2).

%=> zero_or_negative

Test_fun(10).

%=> exactly_ten

</code></pre>

</div>

Elixir

cond do

x > 10 ->

:greater_than_ten

x < 10 and x > 0 ->

:less_than_ten_positive

x < 0 or x === 0 ->

:zero_or_negative

true ->

:exactly_ten

end

test_fun.(44)

#=> :greater_than_ten

test_fun.(0)

#=> :zero_or_negative

test_fun.(10)

#=> :exactly_ten

</code></pre>

</div>

There are two important differences between Elixir’s <code class="highlighter-rouge">cond</code> and Erlang’s <code class="highlighter-rouge">if</code>:

1) <code class="highlighter-rouge">cond</code> allows any expression on the left side while Erlang allows only guard clauses;

2) <code class="highlighter-rouge">cond</code> uses Elixir’s concepts of truthy and falsy values (everything is truthy except <code class="highlighter-rouge">nil</code> and <code class="highlighter-rouge">false</code>), Erlang’s <code class="highlighter-rouge">if</code> expects strictly a boolean;

Elixir also provides an <code class="highlighter-rouge">if</code> function that resembles more imperative languages and is useful when you need to check if one clause is true or false:

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>if x > 10 do

:greater_than_ten

else

:not_greater_than_ten

end

</code></pre>

</div>

<h3 id="sending-and-receiving-messages">Sending and receiving messages</h3>

The syntax for sending and receiving differs only slightly between Erlang and Elixir.

Erlang

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>Pid = self().

Pid ! {hello}.

receive

{hello} -> ok;

Other -> Other

after

10 -> timeout

end.

</code></pre>

</div>

Elixir

<div class="language-elixir highlighter-rouge"><pre class="highlight"><code>pid = Kernel.self

send pid, {:hello}

receive do

{:hello} -> :ok

other -> other

after

10 -> :timeout

end

</code></pre>

</div>

<h2 id="adding-elixir-to-existing-erlang-programs">Adding Elixir to existing Erlang programs</h2>

Elixir compiles into BEAM byte code (via Erlang Abstract Format). This means that Elixir code can be called from Erlang and vice versa, without the need to write any bindings. All Elixir modules start with the <code class="highlighter-rouge">Elixir.</code> prefix followed by the regular Elixir name. For example, here is how to use the UTF-8 aware <code class="highlighter-rouge">String</code> downcase from Elixir in Erlang:

-export([downcase/1]).

downcase(Bin) ->

'Elixir.String':downcase(Bin).

</code></pre>

</div>

<h3 id="rebar-integration">Rebar integration</h3>

If you are using rebar, you should be able to include Elixir git repository as a dependency:

<div class="highlighter-rouge"><pre class="highlight"><code>https://github.com/elixir-lang/elixir.git

</code></pre>

</div>

Elixir is structured similar to Erlang’s OTP. It is divided into applications that are placed inside the <code class="highlighter-rouge">lib</code> directory, as seen in its <a href="https://github.com/elixir-lang/elixir">source code repository</a>. Since rebar does not recognize such structure, we need to explicitly add to our <code class="highlighter-rouge">rebar.config</code> which Elixir apps we want to use, for example:

<div class="language-erlang highlighter-rouge"><pre class="highlight"><code>{lib_dirs, [

"deps/elixir/lib"

]}.

</code></pre>

</div>

This should be enough to invoke Elixir functions straight from your Erlang code. If you are also going to write Elixir code, you can <a href="https://github.com/yrashk/rebar_elixir_plugin">install Elixir’s rebar plugin for automatic compilation</a>.

<h3 id="manual-integration">Manual integration</h3>

If you are not using rebar, the easiest approach to use Elixir in your existing Erlang software is to install Elixir using one of the different ways specified in the <a href="/getting-started/introduction.html">Getting Started guide</a> and add the <code class="highlighter-rouge">lib</code> directory in your checkout to <code class="highlighter-rouge">ERL_LIBS</code>.

<h2 id="further-reading">Further reading</h2>

Erlang’s official documentation site has a nice <a href="http://www.erlang.org/doc/programming_examples/users_guide.html">collection</a> of programming examples. It can be a good exercise to translate them into Elixir.

Elixir also provides a <a href="/getting-started/introduction.html">Getting Started guide</a> and has <a href="/docs.html">documentation available online</a>.

</div>

<h3>

News: <a href="/blog/2018/07/25/elixir-v1-7-0-released/">Elixir v1.7 released</a>

</h3>

</div>

</form>

</div>

<h3 class="widget-title">Official Channels</h3>

<ul>

<li><a class="spec" href="irc://irc.freenode.net/elixir-lang">#elixir-lang on freenode IRC</a></li>

<li><a class="spec" href="https://twitter.com/elixirlang">@elixirlang on Twitter</a></li>

</ul>

</div>

<h3 class="widget-title">Join the Community</h3>

<ul>

<li><a class="spec" href="http://elixirforum.com">Elixir Forum</a></li>

<li><a class="spec" href="https://elixir-slackin.herokuapp.com/">Elixir on Slack</a></li>

<li><a class="spec" href="https://discord.gg/elixir">Elixir on Discord</a></li>

<li><a class="spec" href="http://elixir.meetup.com">Meetups around the world</a></li>

<li><a class="spec" href="https://github.com/elixir-lang/elixir/wiki">Wiki with events, resources and talks organized by the community</a></li>

</ul>

</div>

<div class="mini-docu-copy">Watch the Elixir mini-documentary!</div>

</div>

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