Comments, suggestions, … are welcome! For example, I just wrote some code today that catches all Throwables. GitHub is home to over 50 million developers working together to host and review code, manage projects, and build software together. I highly recommend building some libraries and seeing for yourself! SHOULD mutate state in actors only with "context.become", 5.3. Scala Best Practices. SHOULD avoid contention on shared reads, 4.9. Growing isn’t easy, but using these best practices from the beginning can make growth much smoother. Scala Best Practices – A good place to start. Collection of best practices for the Scala programming language - nrinaudo/scala-best-practices Once you set this options and use sealed with your abstract classes for pattern matching, the Scala compiler will always stop building your project whenever a warning is produced, which is great.. SHOULD be mindful of the garbage collector, 3.5. Learn, play and contribute. We use essential cookies to perform essential website functions, e.g. By which I am suggesting that "best practices for Scala" encompasses both Scala and everything in programming. Copyright © 2015-2016, Some Rights Reserved. First Online: 26 February 2015. Please read this guide carefully. What other best practices should Scala projects follow? People Repo info Activity. @alexandru. I come from a Java Background where I use .properties file and load them at the start. download the GitHub extension for Visual Studio, 1.1. Based on my learnings, I created a checklist of 30 best practices for creating, transmitting, and analyzing logs. This guide attempts to distill our experience into short essays, providing a set of best practices. If nothing happens, download GitHub Desktop and try again. I’m clearly not the best Scala developer out there and might have gotten things wrong, or right for the wrong reasons. A collection of Scala best practices. Millions of developers and companies build, ship, and maintain their software on GitHub — the largest and most advanced development platform in the world. MUST NOT put things in Play's Global, 3.3. SHOULD enforce a reasonable line length, 1.2. SHOULD NOT wrap purely CPU-bound operations in Futures, 4.4. they're used to gather information about the pages you visit and how many clicks you need to accomplish a task. Notwithstanding some criticism, the tagless final pattern continues to gain popularity among the Scala community. July 29, 2020. Scala Best Practices. For a variety of reasons, including removing null values from your Scalacode, you want to use what I call the Option/Some/None pattern. Scala for the Intrigued - Duration: 1:42:04. Work fast with our official CLI. As part of the Scala community, there are definitely some best practices we should all be aware of and some that we may not know but as Nicolas Rinaudo says once we do we will probably wish someone had told us sooner! SHOULD use immutable data structures, 2.3. @maximn. Remarks. Licensed under CC BY 4.0. MUST NOT leak the internal state of an actor in asynchronous closures. Andreas Jim-Hartmann May 8 Originally published at Medium on Apr 21 ・10 min read. Something that’s becoming increasingly obvious is that Scala developers follow a certain set of unspoken rules without really thinking about them, and never really explain them to beginners. I often find myself, both professionaly and otherwise, having to explain bits of Scala to newcomers to the language (but usually not new to programming). Maxim Novak. This is not helping Scala’s reputation as a hard to learn language, which is unfortunate - it’s a language I enjoy and wish more people would learn. CSV and JSON Tips and Best Practices When persisting and compressing CSV and JSON files, make sure they are splittable, give high speeds, and yield reasonable compression. hi … Use this to return things over using return directly. I often find myself, both professionaly and otherwise, having to explain bits of Scala to newcomers to the language (but usually not new to programming). This is an excerpt from the Scala Cookbook (partially modified for the internet). @maximn. Scala Best Practices. myPath := baseDirectory.value / "licenses" In Java (and thus in Scala), a relative File is relative to the current working directory. Learn more. We’ve covered a lot of ground so far. Code samples demonstrate concepts along the way. I'll be developing in Scala. Open an issue to make suggestions, or create a pull request ;-). Scala Language Best Practices. You signed in with another tab or window. We use optional third-party analytics cookies to understand how you use GitHub.com so we can build better products. Reading Time: 4 minutes. 2.6k Downloads; Abstract. It’s a great read for developers who already had a first introduction to the language. Even more best practices from Alexandru on github Here is some good information about picking good names for classes/functions etc and clean coding. Then I have a class used to access the different value of my properties. Scala Puzzlers by Andrew Phillips and Nermin Šerifović — Paid — Intermediate SHOULD evolve the state of actors only in response to messages received from the outside, 5.2. Compare remainder to 0 when checking for oddness, Add explicit type annotations to implicits, Avoid unicode versions of ASCII operators, Make implicit names as unique as possible, Start independent Futures outside of a for-comprehension, Do not compute the size of a collection to check for emptiness, Do not return Option from custom extractors, Add explicit type annotations to public members, Declare ADT data constructors in the companion object, Make ADTs subtypes of Product and Serializable, Declare abstract fields as paren-less methods, Use override when implementing abstract members, Creative Commons Attribution 4.0 International License. SHOULD NOT use "var" as shared state, 2.16. MUST NOT rely on a SBT or IDE plugin to do the formatting for you, 1.4. Scala currently infers the most specialized type possible, because in Scala the return type on functions is covariant, so you might actually get a really ugly type back SHOULD NOT define case classes nested in other classes: You should never define nested case classes inside another object/class because it messes with Java’s serialization. Learn more. Use vars, mutable objects, and methods with side effects when you have a specific need and justification for them.-- Programming in Scala, by Odersky, Spoon, and Venners. Coding Best practices to follow with Scala March 25, 2019 March 25, 2019 Shubham Dangare Scala Best Practices, Clean code, scala. SHOULD use a separate thread-pool for blocking I/O, 4.7. There are two basic categories of ADTs: 1. product types 2. sum types Scala returns the last expression in a function. This is great - being new to scala I can already see some mistakes I have made identified here and good solutions. Tagless Final in Scala: Best Practices # programming # functional # taglessfinal # scala. This is related to the no hard coding best practice because the proper way involves referencing the baseDirectory setting. Use Git or checkout with SVN using the web URL. SHOULD NOT use Any or AnyRef or isInstanceOf / asInstanceOf, 2.13. Scala in Depth covers a full range of best practices and examples to help get started and solve common Scala issues. Authors; Authors and affiliations; Vishal Layka; David Pollak; Chapter. SHOULD NOT declare abstract "var" members, 2.7. Thanks for hanging in and reading all this way. Scala Best Practices. MUST serialize dates as either Unix Timestamp or ISO 8601, 2.15. Is this also a good practice in Scala ? they're used to log you in. MUST provide a clearly defined and documented protocol for each component or actor that communicates over async boundaries, 4.10. we are going to have a new rule soon: alexandru/scala-best-practices#32. SHOULD NOT define case classes nested in other classes, 2.18. Solve Complete and solve exercises to test your understanding of the concepts. Writing code that follows these practices will serve you well beyond CS 18, because when your code is well structured and well organized, it is easier to read, debug, test, optimize, etc. They’re widely used in Scala due, mostly, to how well they work with pattern matching and how easy it is to use them to make illegal states impossible to represent. Primitives like String, Int, Boolean are always immutable. A collection of best practices, friendly to people that want to contribute. The Scala community is supportive and participating is rewarding. The criticism of "best practices" lists is that everything becomes a "core principle". Our talk about the Scala best practices for pattern matching would be incomplete without a solution to ignore warnings when we don't need them. For more information, see our Privacy Statement. MUST NOT introduce spelling errors in names and comments, 2.2. 1. All public APIs SHOULD BE thread-safe, 4.8. If you’re new to Scala, start here. Scala Exercises is an open source project for learning various Scala tools and technologies. MUST NOT hard-code the thread-pool / execution context, 5.1. Hi @maximn:-) Alexandru Nedelcu. Learn Best Practices in Scala Programming from a professional trainer on your own time at your own desk This visual training method offers users increased retention and accelerated learning. Removing annoying warnings. MUST use Scala's BlockContext on blocking I/O, 4.6. A collection of best practices, friendly to people that want to SHOULD always prefer single producer scenarios, 4.11. We use optional third-party analytics cookies to understand how you use GitHub.com so we can build better products. Everything except, unfortunately, the prime directive: get something working first. For example, the following defines the myPath setting to be the /licenses/ directory. Anyone starting a project in Scala, expanding a Scala project, or looking to establish coding standards as a means for helping junior Scala programmers come up to speed, will value this overview of Scala best practices by Scala expert Joshua Backfield. This short article about Scala best practices has some redundant information as above, but it also has some unique information and insights. I'm creating the project from scratch and I was wondering what to do with properties. SHOULD NOT update a "var" using loops or conditions, 2.5. First, you are the programmer and second, you want to be a … As the number of engineers in our Scala ecosystem has continued to grow, and more complex services are emerging, there has been a need for developing conventions and best practices. Learn Exercises start with the basics and progress with your skill level. Learn more, We use analytics cookies to understand how you use our websites so we can make them better, e.g. Public functions SHOULD have an explicit return type, 2.17. 0. Scala Days Conferences 7,490 views. contribute. Scala best practices I wish someone'd told me about - Nicolas Rinaudo - Duration: 48:49. best practice SCALA works with our Grocery, FMCG, Home Appliance and Homeware forum member clients to ensure that, in a perpetually changing marketplace, their supply chain and logistics operations embrace the most optimal practices within the industry to … This site is meant to address that, by listing and explaining all these rules I wish someone’d told me about when I was learning the language. 48:49. If nothing happens, download the GitHub extension for Visual Studio and try again. I’ve helped dozens of large companies set up log management solutions, and I’ve seen the best and the worst. Apart from these the recommended approach is to use Scala case classes which are immutable; Messages can be any kind of object but have to be immutable. Scala Good Coding Practices Spring 2020 Contents 1 Introduction This document is the CS 18 \good" coding practices guide. Or, if you’re interested in a problem (exception) that occurred while processing code, you may want to return Try/Success/Failure from a method instead of Option/Some/None. SHOULD NOT apply optimizations without profiling, 3.4. SHOULD use appropriate abstractions only where suitable, 4.3. Prefer vals, immutable objects, and methods without side effects. Algebraic Data Types (ADTs for short) are a way of structuring data. MUST NOT use Java's Date or Calendar, instead use, 2.12. Breaks even the most complex applications down into simplistic steps Comes with Extensive Working Files Version: 1.2 Updated at: 2016-06-08 Table of Contents. Learn more. This work is licensed under a Creative Commons Attribution 4.0 International License. If you see areas that could be improved on, feel free to open an issue! Rather than using random examples from Scala projects in the wild, these are meant as my evolving “best” way of doing things. ZIP compression is not splittable, whereas Snappy is splittable; … You can always update your selection by clicking Cookie Preferences at the bottom of the page. Preface SHOULD use head/tail and init/last decomposition only if they can be done in constant time and memory, 3.2. In this talk at Scala Days Nicolas discusses the Scala best practices he wishes someone had told him. @alexandru. Ping me in the comments or email me if you have other suggestions for library best practices. Our use of Scala is mainly for creating high volume services that form distributed systems — and our advice is thus biased — but most of the advice herein should translate naturally to other domains. Maxim Novak. If nothing happens, download Xcode and try again. 2. Reach for them first. I love the idea of options, but in practice it is making my code a lot harder to read. When I first came to Scala from Java, I was happy with the small things, including eliminating a lot of ;, (), and {} characters, and writing more concise, Ruby-like code. This is the introduction to Chapter 20, Idioms (Scala best practices). MUST NOT include classes, traits and objects inside package objects, 2.19. hi Alexandru Nedelcu. Foreword. If you are reading this blog there may be two reasons. MUST NOT use parameterless ConfigFactory.load() or access a Config object directly, 4.1. I have surfed the internet trying to find some sort of equivalent to the best practices of the object oriented world, but without much luck. MUST NOT use "var" inside a case class, 2.6. I can find some "best practices" for functional programming but Spark just adds an extra layer, because performance is such a major factor here. Clean Code Best Practices in Scala Naming, functions, and TDD — these are Scala clean-code essentials. Scala can’t enforce immutability (yet) so this has to be by convention. SHOULD avoid concurrency like the plague it is, 4.2. MUST NOT throw exceptions for validations of user input or flow control, 2.11. Spelling errors in names and comments, 2.2 introduction this document is the introduction to Chapter 20, (... The comments or email me if you ’ re new to Scala, start here modified for the Scala language... Language - nrinaudo/scala-best-practices the Scala best practices ) third-party analytics cookies to understand how use... Classes/Functions etc and clean coding classes/functions etc and clean coding over using directly! Covers a full range of best practices '' lists is that everything becomes a `` core principle.! Context, 5.1 use a separate thread-pool for blocking I/O, 4.7 your of. Null values from your Scalacode, you want to contribute Chapter 20, Idioms Scala! Use this to return things over using return directly for you, 1.4 providing set. Basics and progress with your skill level and clean coding 2016-06-08 Table of.. A pull request ; - ) `` best practices from Alexandru on GitHub here is some good information the!, 2.13 for creating, transmitting, and analyzing logs '' members,.. Use GitHub.com so we can make them better, e.g identified here and good.! Include classes, 2.18 to read try again short essays, providing a of! Or ISO 8601, 2.15 to gather information about picking good names for classes/functions etc clean. Without side effects I am suggesting that `` best practices and examples help! Is home to over 50 million developers working together to host and review code, manage,. Ve helped dozens of large companies set up log management solutions, and build software.!, 3.3 actor that communicates over async boundaries, 4.10 Visual Studio and try again Originally at! A new rule soon: alexandru/scala-best-practices # 32 growing isn ’ t enforce immutability ( )... Ve seen the best and the worst Scala programming language - nrinaudo/scala-best-practices the community. Download GitHub Desktop and try again you ’ re new to Scala, start here if you reading. Date or Calendar, instead use, 2.12 to use what I call the Option/Some/None pattern 'll developing... As either Unix Timestamp or ISO 8601, 2.15 solve common Scala issues 2020 1... And how many clicks you need to accomplish a task third-party analytics cookies to how! Two reasons a SBT or IDE plugin to do the formatting for you 1.4... Common Scala issues Calendar, instead use, 2.12 in names and comments, 2.2 language!, 1.4 must use Scala 's BlockContext on blocking I/O, 4.7 information as above, but in practice is... Encompasses both Scala and everything in programming need to accomplish a task you see areas that could be on. Of user input or flow control, 2.11 learn Exercises start with the basics progress! To access the different value of my properties seen the best and the worst or ISO,... Community is supportive and participating is rewarding wrap purely CPU-bound operations in Futures 4.4... Except, unfortunately, the following defines the myPath setting to be the < base > /licenses/ directory information picking! Leak the internal state of an actor in asynchronous closures GitHub extension for Visual Studio,.... 'Ll be developing in Scala friendly to people that want to use what I call the Option/Some/None pattern Originally. Only in response to messages received from the beginning can make growth smoother. Information as above, but in practice it is, 4.2 or isInstanceOf / asInstanceOf, 2.13 with context.become... Notwithstanding some criticism, the prime directive: get something working first you ’ new! / asInstanceOf, 2.13 of an actor in asynchronous closures each component or actor that communicates over async boundaries 4.10! Here and good solutions and init/last decomposition only if they can be done in scala best practices time and,! Background where I use.properties file and load them at the bottom of the concepts a Config object directly 4.1... Are always immutable functions should have an explicit return type, 2.17 best and the worst, I just some. S a great read for developers who already had a first introduction to Chapter 20, Idioms ( best. Make growth much smoother Scala in Depth covers a full range of practices. Created a checklist of 30 best practices, friendly to people that want to scala best practices what I call the pattern! Excerpt from the beginning can make them better, e.g ・10 min.. A Config object directly, 4.1 like String, Int, Boolean always. And try again NOT update a `` var '' inside a case,... In programming have other suggestions for library best practices programming language - nrinaudo/scala-best-practices the Scala programming language - the. Popularity among the Scala community is supportive and participating is rewarding to have a new rule soon alexandru/scala-best-practices. Authors ; authors and affiliations ; Vishal Layka ; David Pollak ; Chapter bottom! 2016-06-08 Table of Contents it also has some redundant information as above, but using these best practices Scala... Selection by clicking Cookie Preferences at the start Creative Commons Attribution 4.0 License! 1 introduction this document is the introduction to the language, 2.17 no hard coding best practice the. On, feel free to open an issue download the GitHub extension Visual... A SBT or IDE plugin to do with properties do with properties or isInstanceOf / asInstanceOf,.! 1.2 Updated at: 2016-06-08 Table of Contents or isInstanceOf / asInstanceOf,.. '' members, 2.7 ’ ve seen the best and the worst a of. Like the plague it is, 4.2 for library best practices from beginning... Essays, providing a set of best practices and examples to help get started and solve common Scala.. Protocol for each component or actor that communicates over async boundaries, 4.10 has to be convention! Using return directly types I 'll be developing in Scala: best practices, friendly to people that to. For creating, transmitting, and I was wondering what to do the formatting for you,.. Your understanding of the concepts need to accomplish a task two reasons NOT use parameterless ConfigFactory.load ( ) access! 'M creating the project from scratch and I was wondering what to do with.. No hard coding best practice because the proper way involves referencing the baseDirectory setting, and! ( ADTs for short ) are a way of structuring Data ADTs for short are! Developer out there and might have gotten things wrong, or right for the wrong.... Primitives like String, Int, Boolean are always immutable Java Background where I use.properties file load., 2.12 learnings, I just wrote some code today that catches all Throwables it has. Call the Option/Some/None pattern to understand how you use our websites so we can build better products great. Input or flow control, 2.11 user input or flow control, 2.11 happens, download GitHub. A new rule soon: alexandru/scala-best-practices # 32 I/O, 4.6 the web URL functions, e.g Config directly! In Depth covers a full range of best practices scala best practices lists is that everything becomes a core! The proper way involves referencing the baseDirectory setting new rule soon: #. Pull request ; - ) he wishes someone had told him in response to messages received from the outside 5.2... Your understanding of the page 50 million developers working together to host and review code, manage projects, analyzing... At Scala Days scala best practices discusses the Scala Cookbook ( partially modified for the internet ) providing! Basics and progress with your skill level execution context, 5.1 some mistakes I have a used! Both Scala and everything in programming access a scala best practices object directly, 4.1 messages received from beginning! Input or flow control, 2.11 to use what I call the Option/Some/None pattern garbage... So this has to be the < base > /licenses/ directory must provide a clearly defined and protocol! Of large companies set up log management solutions, and analyzing logs case classes nested in other classes traits. Taglessfinal # Scala your skill level '' members, 2.7, providing a set of practices... Use parameterless ConfigFactory.load ( ) or access a Config object directly, 4.1 Option/Some/None pattern build software together they! And reading all this way Studio, 1.1 practices, friendly to people that want to use what I the! A checklist of 30 best practices and examples to help get started and solve common Scala issues you have suggestions. Progress with your skill level the worst and try again or isInstanceOf / asInstanceOf,.... Without side effects them better, e.g provide a clearly defined and protocol. My learnings, I created a checklist of 30 best practices, friendly to people that want use..., download Xcode and try again are two basic categories of ADTs 1.! And reading all this way where I use.properties file and load them at the bottom of the garbage,! Can already see some mistakes I have made identified here and good solutions licensed under a Commons. Going to have a class used to access the different value of my properties like the plague it making! Referencing the baseDirectory setting, 2.15 actor that communicates over async boundaries,.. Is an excerpt from the beginning can make them better, e.g the web URL soon... Use analytics cookies to understand how you use our websites so we build... Creating, transmitting, and methods without side effects be done in time... Case class, 2.6 Boolean are always immutable leak the internal state of an in... Appropriate abstractions only where suitable, 4.3 to access the different value of my properties ve the... Popularity among the Scala programming language - nrinaudo/scala-best-practices the Scala best practices for creating, transmitting and...