Getting Started with Elixir Programming Language

If you have been reading blog posts, hacker news threads, your favorite developers tweets or listening to podcasts, at this point you’ve probably heard about the Elixir programming language. The language was created by José Valim, a well known developer in the open-source world. You may know him from the Ruby on Rails MVC framework or from devise and simple_form ruby gems him and his co-workers from the Plataformatec have been working on in the last few years.

According the José Valim, Elixir was born in 2011. He had the idea to build the new language due the lack of good tools to solve the concurrency problems in the ruby world. At that time, after spending time studying concurrency and distributed focused languages, he found two languages that he liked, Erlang and Clojure which run in the JVM. He liked everything he saw in the Erlang language (Erlang VM) and he hated the things he didn’t see, like polymorphism, metaprogramming and language extendability attributes which Clojure was good at. So, Elixir was born with that in mind, to have an alternative for Clojure and a dynamic language which runs in the Erlang Virtual Machine with good extendability support.

Getting Started with Elixir Programming Language

Elixir describes itself as a dynamic, functional language with immutable state and an actor based approach to concurrency designed for building scalable and maintainable applications with a simple, modern and tidy syntax. The language runs in the Erlang Virtual Machine, a battle proof, high-performance and distributed virtual machine known for its low latency and fault tolerance characteristics.

Before we see some code, it’s worth saying that Elixir has been accepted by the community which is growing. If you want to learn Elixir today you will easily find books, libraries, conferences, meetups, podcasts, blog posts, newsletters and all sorts of learning sources out there as well as it was accepted by the Erlang creators.

Let’s see some code!

Install Elixir:

Installing Elixir is super easy in all major platforms and is an one-liner in most of them.

Arch Linux

Elixir is available on Arch Linux through the official repositories:

pacman -S elixir


Installing Elixir in Ubuntu is a bit tidious. But it is easy enough nonetheless.

wget && sudo dpkg -i erlang-solutions_1.0_all.deb
apt-get update
apt-get install esl-erlang
apt-get install elixir


Install Elixir in OS X using Homebrew.

brew install elixir

Meet IEx

After the installation is completed, it’s time to open your shell. You will spend a lot of time in your shell if you want to develop in Elixir.

Elixir’s interactive shell or IEx is a REPL – (Read Evaluate Print Loop) where you can explore Elixir. You can input expressions there and they will be evaluated giving you immediate feedback. Keep in mind that your code is truly evaluated and not compiled, so make sure not to run profiling nor benchmarks in the shell.

The Break Command

There’s an important thing you need to know before you start the IEx RELP – how to exit it.

You’re probably used to hitting


to close the programs running in the terminal. If you hit


in the IEx RELP, you will open up the Break Menu. Once in the break menu, you can hit


again to quit the shell as well as pressing



I’m not going to dive into the break menu functions. But, let’s see a few IEx helpers!


IEx provides a bunch of helpers, in order to list all of them type:



And this is what you should see:

Those are some of my favorites, I think they will be yours as well.

  • 1

    as we just saw, this function will print the helper message.

  • 1

    which is the same function, but now it expects one argument.

For instance, whenever you want to see the documentation of the


method you can easily do:

Probably the second most useful IEx helper you’re going to use while programming in Elixir is the


, which compiles a given elixir file (or a list) and expects as a second parameter a path to write the compiled files to.

Let’s say you are working in one of the Elixir exersices, the Anagram exercise.

So you have implemented the


module, which has the method


in the anagram.exs file. As the good developer you are, you have written a few specs to make sure everything works as expected as well.

This is how your current directory looks:

Now, in order to run your tests against the Anagram module you need to run/compile the tests.

As you just saw, in order to compile a file, simply invoke the


executable passing as argument path to the file you want to compile.

Now let’s say you want to run the IEx REPL with the Anagram module accessible in the session context. There are two commonly used options. The first is you can require the file by using the options


, something like

iex -r anagram.exs

. The second one, you can compile right from the IEx session.

Simple, just like that!

Ok, what about if you want to recompile a module? Should you exit the IEx, run it again and compile the file again? Nope! If you have a good memory, you will remember that when we listed all the helpers available in the IEx RELP, we saw something about a recompile command. Let’s see how it works.

Notice that this time, you passed as an argument the module itself and not the file path.

As we saw, IEx has a bunch of other useful helpers that will help you learn and understand better how an Elixir program works.

Basics of Elixir Types


There are two types of numbers. Arbitrary sized integers and floating points numbers.


Integers can be written in the decimal base, hexadecimal, octal and binary.

As in Ruby, you can use underscore to separate groups of three digits when writing large numbers. For instance you could right a hundred million like this:









Floare are IEEE 754 double precision. They have 16 digits of accuracy and a maximum exponent of around 10308.

Floats are written using a decimal point. There must be at least one digit before and after the point. You can also append a trailing exponent. For instance 1.0, 0.3141589e1, and 314159.0-e.


Atoms are constants that represent names. They are immutable values. You write an atom with a leading colon


and a sequence of letters, digits, underscores, and at signs


. You can also write them with a leading colon


and an arbitrary sequence of characters enclosed by quotes.

Atoms are a very powerful tool, they are used to reference erlang functions as well as keys and Elixir methods.

Here are a few valid atoms.

:name, :first_name, :"last name",  :===, :is_it_@_question?


Of course, booleans are true and false values. But the nice thing about them is at the end of the day, they’re just atoms.


By default, strings in Elixir are UTF-8 compliant. To use them you can have an arbitrary number of characters enclosed by




. You can also have interpolated expressions inside the string as well as escaped characters.

Be aware that single quoted strings are actually a list of binaries.

Anonymous Functions

As a functional language, Elixir has anonymous functions as a basic type. A simple way to write a function is

fn (argument_list) -> body end

. But a function can have multiple bodies with multiple argument lists, guard clauses, and so on.

Dave Thomas, in the Programming Elixir book, suggests we think of fn…end as being the quotes that surround a string literal, where instead of returning a string value we are returning a function.


Tuple is an immutable indexed array. They are fast to return its size and slow to append new values due its immutable nature. When updating a tuple, you are actually creating a whole new copy of the tuple self.

Tuples are very often used as the return value of an array. While coding in Elixir you will very often see this,

{:ok, something_else_here}


Here’s how we write a tuple:



Pattern Matching

I won’t be able to explain everything you need to know about Pattern Matching, however what you are about to read covers a lot of what you need to know to get started.

Elixir uses


as a match operator. To understand this, we kind of need to unlearn what we know about


in other traditional languages. In traditional languages the equals operator is for assignment. In Elixir, the equals operators is for pattern matching.

So, that’s the way it works values in the left hand side. If they are variables they are bound to the right hand side, if they are not variables elixir tries to match them with the right hand side.

Pin Operator

Elixir provides a way to always force pattern matching against the variable in the left hand side, the pin operator.


In Elixir, Lists look like arrays as we know it from other languages but they are not. Lists are linked structures which consist of a head and a tail.

Keyword Lists

Keyword Lists are a list of Tuple pairs.

You simply write them as lists. For instance: [{:one, 1}, 2, {:three, 3}]. There’s a shortcut for defining lists, here’s how it looks: [one: 1, three: 3].

In order to retrieve an item from a keyword list you can either use:

Keyword.get([{:one, 1}, 2, {:three, 3}], :one)

Or use the shortcut:

[{:one, 1}, 2, {:three, 3}][:one]

Because keyword lists are slow when retrieving a value, in it is an expensive operation, so if you are storing data that needs fast access you should use a Map.


Maps are an efficient collection of key/value pairs. The key can have any value you want as a key, but usually should be the same type. Different from keyword lists, Maps allow only one entry for a given key. They are efficient as they grow and they can be used in the Elixir pattern matching in general use maps when you need an associative array.

This article originally appeared on Toptal

Flowers near office

from Instagram:

Windows Vs Linux – One more time

Tux, as originally drawn by Larry Ewing
Image via Wikipedia

One of the most written and commented articles has to be Linux vs Windows (of course there are competitors like vim vs emacs) but none has been covered so much as Linux vs Windows. So, what am I going to write here which is not covered earlier in so many other posts. Well a little different perspective 🙂


We will take this post in points so that we do not divert and its easier for you to comment with quotes to point number 🙂

1) These are for complete different segments of users.

Windows is for everyone and Linux is for geeks and fan-boy‘s. Well, not that I agree with this but lets face the fact. Windows is OS on which all the drivers works and you dont have to worry about which Webcam I need to buy or which scanner will work.

The reason for this is multi-fold but does that matter to everyday users.

2) Cost factor.

This is something that keeps popping up every time there is some discussion like this. I don’t think that anyone using Linux is using it because it is free. If there is someone using the FREE OS just because it is free then I for one would definitely like to understand if the same person would use Windows if it was free.

BTW, I guess in China people don’t even know that Windows license’s are paid.

3) Ease of Use

People using Windows have always this notion that Linux is difficult to use. I found it the other way round. I find myself limited in ways to work on Windows (Oh and yes, I am stuck with Windows here for last around 2 months). Its mostly a question of perception. There are still things in Linux that you might have to do in the so called bash/console/terminal/command prompt, call it what you want to. But mostly that is the case for doing things faster and otherwise you probably would not need to open a terminal ever.

But if you go to any of the forums, you will definitely get suggestions to open a terminal first. Why, because you will be getting suggestions from veterans in the field. These guys have been using Linux since the days when there was no GUI or using GUI was considered sin. Just kidding but seriously you can do things much faster in a “command window”.

4) Different Filesystems.

Windows uses FAT/vFAT/NTFS and so on whereas Linux uses some 83 other types of FS. Mostly widely used being ext2, ext3, ext4 and reiser (I guess ). Why does it matter to you? Because you can use (read as read/write) any of the windows Filesystems on the Linux box natively but not the other way round. So, be careful with this.

5) File-type and associations.

Files and folders are same on Linux and Windows. Does not make much of a difference. Both are handled in similar manner. Not the same if you look a little deeper. This is one thing that confuses most who are new to Linux.

In Windows the File type and the action of double click is based on the extension of the filename. So, if I have a file with name “a.txt” then the default text editor would be used. That is not the case in Linux (well the File Manager uses similar concept , see I told you it is confusing). The file type in linux is determined by the header in the file that is stored along with the files and not seen by us normally. Thus allowing you to store a pdf file with “.txt” extension and still be able to use pdf viewer to open the file. How cool is that 🙂 or how confusing is that 🙁

6) Applications

Some would say that the number of applications available on Windows is much more that available on Linux. Oh yeah, surely and how many of them you can use or rather how many of them are required. If not all, most of the useful ones are paid. So, you need to buy a license to use it. This is not the case with Linux, you have some couple of thousands of applications with mostly very decent GUI’s developed by Open Source advocates. And they were actually generous enough to compile it to “.exe” for the windows also.

7) Fanboys

The main reason for liking any one of the OS is probably because you met a Windows fanboy first so you also became a Windows fanboy. If you met a Linux fanboy first then you would become a Linux fan. Okay, there are chances that you met a more hardcore fanboy of the other side of the war, then he might convert you to his side and win over you.

I will leave it at abrupt end, so that it can tickle some more thoughts in both you and me 🙂

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