Elixir cheatsheet

Alias allows you to import a module into another module and access it using a different name. This is commonly used to access nested modules more conveniently. Elixir provides directives for reusing modules in your project.

Making statements based on opinion; back them up with references or personal experience. Connect and share knowledge within a single location that is structured and easy to search. Pattern matching isn’t limited to just variables in Elixir, it can be applied to function signatures as we will see in this section. For one of the lessons, I created slides with a syntax comparison of Elixir, Ruby, and JavaScript. In this article, I would like to share that with you. Please note that some details like version numbers may differ a bit in your session; that’s not important.

elixir % syntax

Elixir’s case statement operates on pattern matching – you can use it to match values or structures. It’s important to note that Elixir is a compiled language. So unlike a language like Javascript or Ruby, you do not import one file into another. Instead, modules are compiled Startup CTO together and can be accessed from any .ex files in the project. This chapter 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.

All data structures functions employ zero-based access. The reason for this behavior is that Elixir pattern-matches the arguments that a function is called with against the arity the function is defined with. In Elixir and many functional languages, functions are first class citizens. We will learn about the types of functions in Elixir, what makes them different, and how to use them. Functional Programming – It is a well-designed programming language that promotes a coding style to enable developers to write short, fast, and maintainable code.

Added Lisp-style macros

A variable can store any data type; it is not restricted to the examples above. 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 ;. Erlang and Elixir have the same data types for the most part, but there are a number of differences.

elixir % syntax

You must already have Installed Elixir on your machine. You can choose to run elixir using a Repl by executing .ex files on your computer or in the Interactive Elixir environment. The subject of the function is always the first argument. And comma , is used to evaluate multiple expressions within one context . In Elixir, expressions are delimited by a line break or a semicolon ;. This section goes over some of the syntactic differences between the two languages.

The keys of the structs are not changeable once defined. Instead of initializing a variable in the function, we add one more argument to the function. Then we call it again What is Model-View and Control? and again, each time decreasing times and increasing acc. I have left the implementation details unfinished, and you might have a question or two about what is happening.

Elixir provides functions rem and div for working with integer division and remainder. You can also install Elixir onto your computer and then run elixir files (.ex) directly. The 20% of Elixir syntax you need to read 80% of Elixir code. Erlang’s official documentation site has a nice collection of programming examples. It can be a good exercise to translate them into Elixir. You may keep the shell running while you’re editing the file.

Function syntax

Now you can add any intermediate step and nothing has to be renamed. As soon, as we need to insert some intermediate step, we need to rename User3 to User4 and so on. This is a common issue in a pure FP-languages, and for example in Haskell you should use State-monad to handle such logic. This for me has been a very useful feature to decongest my code. I’m not sure what project had pipes first (should we credit F# or Unix shell itself?). Mix is awesome and IMHO way more stable that rebar .

  • It can be a good exercise to translate them into Elixir.
  • This is commonly used to access nested modules more conveniently.
  • My guess is that the comma indicates that the filtering function follows, but without knowing more about Elixir’s syntax, this isn’t immediately obvious.
  • We will start with the customary ‘Hello World’ program.
  • In this article, I would like to share that with you.

Anything other than false and nil will evaluate as true. It’s important to remember the returned value is not a boolean. The returned value is the actual value evaluated. They are commonly used to compare integers and floats but can also be used to compare other data types for sorting purposes. In addition, Elixir allows for default values for arguments, whereas Erlang does not. Actually, the core syntax is very small, and everything is built around gluing this small syntax with macros.

There is a special syntax to allow named functions be treated in the same manner. Scalac compiles directly to byte code that runs on the JVM. So whereas Scala can do things Java can’t do , there really is nothing Elixir can do that Erlang can’t. Being able to use all of erlang’s inbuilt modules and functions are an advantage. Tl;dr I need to use more dynamically typed functional languages to really appreciate posts like this.

But I would say that Erlang is more verbose to write web-applications. I’m more interested in what the error is about though. We briefly covered guards in the Control Structures lesson, now we’ll see how we can apply them to named functions. Once Elixir has matched a function any existing guards will be tested. If we switch the order of % and person in the list, we will get the same result because each are matching to fred on their own.


As you probably know, Elixir was created by a former Ruby developer, José Valim, and his idea was to keep the beautiful syntax of Ruby in Elixir. @princemaple initially brought the tm-syntax to sublime-syntax and made some improvements. Notice the interpolated Elixir code is colored correctly. Add an sql macro/function to your project to enjoy SQL highlighting anywhere it’s used. Scalability − Elixir based applications are executed inside lightweight processes which are isolated and where the information is exchanged through messages.

elixir % syntax

Mostly any stuff which is ad-hoc in another languages, is a macro in Elixir, e.g. if/else, case, defmodule, def, etc. Actually, macros are the most important feature in Elixir which made possible all the DSL stuff in Phoenix and Ecto. Another issue with binaries is that Erlang doesn’t have a decent library for Ways to Become a Mobile App Developer working with them as as it does for strings. Of course, you can roll-out your hand-made solution, but it’s a big pain and fragmentation, because nobody would know an API of your library. Also, regexps in Erlang are supported only as a library. There is no operators and first-class support in syntax for them.

But if you write some “low-level” stuff or a common library and want to share it with the whole eco-system, it makes sense to write it in Erlang. In Elixir, everything is put in very logical modules. Also, there are brilliant Enum and Stream modules which unify work with lists, maps and other iterables. And they’re only partially covered by Erlang stdlib. You’d have to go with unix out of those options, F#’s pipe operator is just flipped function application, and is primarily to make up for the poor type inference F# has.

Writing double-quotes inside of a string

Data and transformations applied to it are clearly delineated. For this post, I have gone through all the basic Elixir constructs and collected a few tips that will help you write idiomatic Elixir code without hours of Googling. It should be useful when you attempt your first Elixir project or do Exercism exercises.

Getting started

I had to create a special shortcut in Vim just not to type this mess of characters while programming in Erlang. I don’t have any experience with it, but your question reminded of this article that came up on HN a while ago arguing it’s more than just syntax differences. Basically that it’s more a Clojure/Scala than a Coffeescript.

Erlang has C-like macros – so it’s just a dumb text generation. It also has a very cumbersome parse-transform engine. Parse-transform allows you to make a lot of stuff, but amount of efforts is huge and extension can be very brittle. I wrote quite a simple extension for Erlang once and never used it in production, because I couldn’t be sure it’d work after Erlang version is changed. Erlang doesn’t have a simple way to emulate polymorphism. Elixir, on the contrary, has protocols and you can describe any set of functions that protocol should support.

My guess is that the comma indicates that the filtering function follows, but without knowing more about Elixir’s syntax, this isn’t immediately obvious. You will find a good explanation in AppSignal article about this, I highly recommend you read it, as it is important to understand. In the company I currently work for, we created an Elixir School to help other colleagues start developing in Elixir.

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