This part is very well written, with examples based on Xtext, Spoofax, and MPS. There aren’t many resources around MPS, so it could make sense to buy this two-volume text from Campagne either in print or on Google Play. Viewed 716 times 3. We have already seen a number of examples of domain-specific languages in this book: The Game monad and its associated actions, developed in chapter 11, constitute a domain-specific language for the domain of text adventure game development. The focus is on how the Groovy language can be used to construct domain-specific mini-languages. using the Functional MetaPost library you can write Haskell expressions, which are then translated to MetaPost, MetaPost is run on the generated code and the result of MetaPost can be post-processed in Haskell. There are several causes, but one important factor is resistance from users, especially when they are developers. The book will help you on different levels. We will look at some concrete examples. It is more academic stuff than an industrial-grade language workbench, so I would suggest a bit of caution. Unlike low-level languages, which are applicable across different domains, domain-specific languages (DSLs) specialize in a particular subject area. Indeed, many DBAs are not developers. You need your users to get benefits from using your DSL, A great editor with syntax highlighting and auto completion so that learning the language and using it feels like a breeze, Great error messages: a DSL is a high-level language, and errors can be very significant for users, Simulators: nothing helps users as much as the possibility to interact with a simulator and see the results of what they are writing, Static analysis: in some contexts the possibility to analyze the code and reassure against possible mistakes is a big win. Related to domain-specific programming is end-user programming, which happens when end-users perform simple programming tasks using a macro or scripting language. The technical details were abstracted in the compiler. I’ve had the occasion to work with Markus, and he is simply the best in this field, so if you can learn something from him, do it. With a DSL they get more power and independence because of it. The Joel Test For Programmers (The Simple Programmer Test), My Secret To Ridiculous Productivity. The domain expert could at this point read it and criticize it. We have discussed the importance of a DSL as a communication tool and medium to support co-design. Implementing Domain-Specific Languages with Xtext and Xtend by Lorenzo Bettini. -  Designed by Thrive In computing as in construction, the right tool can make all the difference. Now, I should probably just praise this book and stress how much I have enjoyed it. Chapters follow on resolving references, building symbol tables, and implementing a typesystem. SQL per interrogazioni in basi di dati relazionali, grammatiche YACC per la creazione di parser, espressioni regolari per Analizzatori lessicali specifici, il Generic Eclipse Modeling System per creare linguaggi per diagrammi, Csound, un linguaggio per la sintesi digitale e i linguaggi di input GraphViz e GrGen. Embedded Domain Specific Language means that you embed a Domain specific language in a language like Haskell. Domain Specific Languages (DSLs) are limited forms of computer language designed for a specific class of problems. Confused? Part IV is about scenarios in which DSLs are useful. However, there are also compelling reasons to solve some specific problems with a more specific, appropriate tool. The Cascading Style Sheet language defines the style used to visualize a document. Code can be also executed on Android and Windows Phone emulators. Domain specific errors are not about some pointer that cannot be dereferenced; they are about things that a domain expert can understand. MPS Language Workbench by Fabien Campagne. Domain Specific Languages (DSLs) have been around since I've been in computing, but it's hard to find much information about how to work with them. Unfortunately, I tend to err on the honesty side, so I warn you: this is one of the most boring books I have ever read. They are easier to support and can be used in all sort of contexts. You've probably heard of Java, Visual Basic, C/C++, or C#. It stayed on my night stand for months. If you are interested in learning how to implement an external DSL, do not pick this book. | Powered by WordPress, Sep 18, 2020 / The sections on alternative computational models and code generation are valuable. By, Jun 29, 2020 / When I start to write, I need to swiftly explain what it is I’m writing about; in this case, to explain what a domain-specific language (DSL) is. Questa pagina è stata modificata per l'ultima volta il 28 set 2020 alle 16:45. The book is seven years old, and the techniques may have evolved since the book was written, but the vast majority of the considerations presented in the book are still valid. It contains more examples, a comparison between more tools, tips on building DSLs, and more resources. Do Software Developers Really Need Degrees? For example, the language does not allow connecting a motor to other objects other than through its ports (Figure 3, ports Enabled, Direction and Speed of the TopStepMotor). In this example, we specify that to create the program myExecutable we will need the object files, and once we have them, we will use gcc to link them together. This language will be understood by developers, domain experts, and also by the software, which will be able to execute the instructions specified in the DSL. or an application context (e.g., a web application, database, etc.) As usual, the answer depends on your needs: 1. This is completely and absolutely relevant if you want to build Domain Specific Languages. He writes with clarity, especially about both internal and external DSLs, and the mental models presented in the book are useful and elegant. The book does a good job in teaching you what you need to know to get started on these subjects, but you may have to complete your education with other resources when you want to progress. This is the kind of stuff you need to learn if you want to become a Language Engineer. When talking with your users, technical or not, communicate that the DSL will be a tool for them, designed to support them, and derived from their understanding of the domain at hand. I'm considering doing something with Domain Specific Languages for my undergraduate project. The book starts discussing different parsing algorithms. By, Aug 14, 2020 / Then comes the part about implementation: remember that Markus has a PhD, but he is first of all someone who gets things done. Right now, the material available on the Xtext website is incomparably better than it used to be, and the book from Lorenzo Bettini helped to make that possible. However, if you find internal DSLs as irrelevant as I do, you may be interested in only some portions of this book. Tag the objects that you patch so you don’t break the host language. I really hope you have heard of this quite successful language to define documents. All built on one platform. the chapter “The Structure Aspect” or “Structure In Practice”). I have not used it, so I cannot vouch for it. On the one hand, it make the investments in the code written using DSLs maintain value over time. https://it.wikipedia.org/w/index.php?title=Domain-specific_language&oldid=115763697, Voci non biografiche con codici di controllo di autorità, licenza Creative Commons Attribuzione-Condividi allo stesso modo. Domain specificity is a theoretical position in cognitive science (especially modern cognitive development) that argues that many aspects of cognition are supported by specialized, presumably evolutionarily specified, learning devices. Listen to the developers, work on capturing their experience and embedding it in the design of the DSL or the tooling around it. While it seems nice and easy to use, textX does not generate editor support like Xtext, which is a major difference. Among others he has worked for TripAdvisor and Groupon. These are the foundations to learn how to process the information expressed in your DSL. It is much better to sit at a table and discuss the example we have displayed with a bank representative than it is to show him the hundreds of lines of Java which correspond to those commands, right? There are many reasons why you should really consider Domain Specific Languages. The main idea behind developing a DSL is to provide a programming language for a narrowed down, specific domain. However, if you prefer internal DSLs to external DSLs, or if you want to read every available resource on DSLs, this book may be a good choice. Projectional editors are extremely powerful and exciting, but they are unfamiliar to many users. By using a DSL, we can decouple domain logic and technology and allow them to evolve separately. One thing missing is more advice on language design. The book does not include how to map this domain model to a language, but it is a good complement to other books specific to DSL design. Yacc, Bison and ANTLR are examples of executable variations of BNF DSL. But there are situations where a general programming language just won't work. A typical example is spreadsheet programming using the Excel macro-language. Regular expressions are “little brother” of BNF as they can specify only regular languages. Themes You may build marketing automation software. Active 8 years, 9 months ago. Maybe you write accounting software, and you work with accountants and business consultants. I really like this DSL because the requirements for using it is very low. We can teach them more easily: they are limited in scope so less time and less training are needed to master them, simply because there is less stuff to study. In contrast, a general-purpose language (GPL) can be used for a wide range of business problems and applications. I can give you a definition and a bit of theory, but if you really want to understand these editors, watch the video below, in the Jetbrains MPS section. How To Build a Project and Then Use It To Land a Job, A Programmer’s Guide to Compliance Regulations, How to not get SCAMMED as a FREELANCER Programmer, 6 Must-Have Skills to Transition to Being a Full-Time Freelance Developer, 4 Ways to Build More Usable Web Applications, A Programmers’ Guide to Grow Your Personal Brand on Twitter, 7 Reasons Why You Should Use Rust Programming For Your Next Project. You have seen why Domain Specific Languages are so cool and what benefits they can bring you. Let's see how to build textual languages and supporting tools. Some DSLs are intended to be used by programmers and therefore are more technical, while others are intended to be used by someone who is not a programmer, and therefore they use less geeky concepts and syntax. That is no accident: Jetbrains has invested significantly in developing it over more than a decade. The same document can also be consumed differently by people with disabilities. I suggest looking into this book only when you feel comfortable with all the topics explained in Volume I. You can combine different notations and support all sort of representation you need for your case. Un domain-specific language (in acronimo DSL), in italiano linguaggio di dominio specifico nello sviluppo software e nell'ingegneria di dominio è un linguaggio di programmazione o un linguaggio di specifica dedicato a particolari problemi di un dominio, a una particolare tecnica di rappresentazione e/o a una particolare soluzione tecnica. You don’t need macros in order to have a DSL: every data structure and every function you define in your module is part of your Domain-specific language. They let you focus on the important concepts. They are the domain experts. Recently though, there has been somewhat of a revolution in this area, with tools being developed which greatly simplify the writing of compilers. E.g. So we just had to change the DSL compiler to preserve the value of the logic and make it usable in a more modern context. However, you do not need to be trained as a developer to learn SQL. Because the DSL captured only the logic, which was the really valuable part of the programs, and an extremely important asset for the company. You are probably familiar with General Purpose Languages, like Java or Python, which are able to express every possible algorithm. In the meantime, the browsers have been completely rewritten multiple times, but the logic can be ported to new technologies. In this sense, a domain is a narrow area of interest. It is amazing to think that we could have defined HTML pages 20 years ago when most people had desktop computers attached to monitors with a resolution of 640×480 pixels, and now those same pages can be rendered on the browser running on our smartphones. Domain Specific Languages (DSLs) are specialized languages carefully crafted to serve one single goal. Then there are chapters about working with the Abstract Syntax Tree, extracting information, and transforming it. Involve them in the design of the DSL. Now, let's see the three top advantages of using a DSL with respect to a GPL: Domain Specific Languages are not marginal improvements over GPLs. Here, we are going to look at a few alternatives: some specifics on building textual DSLs, and one other that is intended to build graphical languages, or languages based on less common notations. You need to win the support of users. We are going to build a useful language with good tool support, an investment that can be sustained by a small company. There is not much on external DSLs: the author briefly discusses Xtext and then spends a chapter on using Scala parser combinators to build external DSLs. In particular, they can dramatically increase productivity and change how developers and domain experts communicate. Datalog could be considered a Domain-Specific language. I worked with them re-engineering the compiler, and the same code of their DSL is now used to generate reactive web applications. You need to represent all the specific tax rules to apply in a given context, and you would need an accountant to explain them to you. I’ve reviewed the second edition of this practical and enjoyable book. The only thing missing is a discussion on how to design DSLs, but since that isn’t the goal of this book, it’s not a big deal. He got a PhD on Polyglot Software Development, and he has been working in Italy, Germany, Ireland, and France. Still, they may resist adopting it if they perceive it as too difficult or if they feel it does not match their way of thinking. In this case, a programming language can be easy to understand for you but read as complete gibberish to domain experts. If you have never used MPS before, it will take some time. Specific tools offer support for specific languages. DSLs are very common in computing: examples include CSS, regular expressions, make, rake, ant, SQL, HQL, many bits of Rails, expectations in JMock, graphviz's dot … Esempi di DSL includono Logo per bambini, Verilog e il linguaggio di descrizione hardware VHSIC, i linguaggi R ed S per la statistica, Mata per la programmazione matriciale, Mathematica e Maxima per i simboli matematici, formule in fogli di calcolo e macro. Domain Specific Languages can serve all sorts of purposes. There are 15 chapters dedicated specifically to external domain specific languages. By, Apr 27, 2020 / He is addicted to GitHub, where it contributes to JavaParser and JavaSymbolSolver. Generally, DSLs are developed in close coordination with the experts in the field for which the DSL is being designed. The only caveat is that Xtext is part of a complex ecosystem, so if you really want to become an expert of Xtext, you need to learn EMF and Xtend. You have probably heard of SQL. In the case that Xtext is not a good fit for your textual language, you may want to consider some alternatives. This two-part article is aimed at experienced C# .NET programmers who wish to write their own little computer languages (see part two here). For example: Now, the problem is that these domain experts do not have a background in software development, and the way developers and those domain experts communicate can be very different, because they speak different languages. If your DSL is intended for non-developers, it is generally easier to win their support. Ask Question Asked 8 years, 9 months ago. For instance, specific browsers for people with impaired sight can help them consume a document defined with HTML. We are not building the next Java or C#, so we are not going to pour tens of years into building an extra-complex compiler or an IDE with tons of features. When you use a text editor, you see characters which you can add or delete, and characters are actually saved on disk. When is the last time you had a Null Pointer Exception when working with HTML or SQL? Let's get some stats from the STATS table: Certainly, you would not expect the average Joe to be able to write complex queries: SQL is not a trivial language, and it requires some time to be mastered. Another advantage of hiding technical details is productivity. https://docs.microsoft.com/.../modeling/about-domain-specific-languages You may build software for the automotive industry. Finally, Terence explains how to use the information you have processed by building an interpreter or a code generator. In addition to that, you will learn some good principles of DSL design. If you want to get a better feeling of how textX works, take a look at this video. Now, let's see why you should use one, and then look at how to build one. These scenarios will then be executable as tests to verify whether the application meets the expectations. It is important, it is useful, it is great, but it is just so plain and long. Because you are giving them a superpower: the ability to do something on their own. I guess it is a good example of what can be achieved with DSLs. However, if you are ready to make the investment, it can revolutionize your processes. By, May 25, 2020 / As the technology changes, you can change the interpreter processing DSL code, but the DSL code can stay the same. So it was disheartening at first, but over time the community seemed to improve a lot. Think about the time spent reasoning about deallocating memory or choosing which implementation of a list would perform best for the case at hand. They started building this DSL 30 years ago, and at that time they generated console applications. Domain Specific Languages are different: their strength lies in doing only one thing, but doing it well. Domain-Specific Languages Patterns Monkey Tag. In practice, however, reaching a point where domain experts can use the DSL autonomously is rare. (I’m Using It Now), Copyright 2018 by Simple Programmer. Fewer things can possibly go wrong when using a DSL. This may be in some XML format, or it may be in a binary format. Xtext is a solid solution to build textual languages, and in many cases it is your best choice. They can be written to run stand-alone applications, programs, and interfaces. Like many other developers, I switched to IntelliJ some years ago, and I was missing a way to easily build editors for IntelliJ IDEA. When creating an Internal Domain-Specific Language inside a language like Ruby you generally need to modify objects from the host’s core library -arrays or strings for example. Plus, they misspelled my name (-1 point for that). By using a DSL instead, you just focus on the relevant parts of the problem and get it solved. Those are instructions for recognizing the structure of a piece of text. Aside from the practical benefits, I find the topic extremely fascinating. What you should get out of this book is the importance of capturing the domain in all of your software artifacts. 1. He writes about designing new languages (DSLs and GPLs), building parsers, editors, compilers, and interpreters at https://tomassetti.me. Domain Specific Languages by Martin Fowler. A domain-specific language (DSL) is a language meant for use in the context of a particular domain. You probably think only about textual languages, but Domain Specific Languages are broader than that. They are safer. I have not yet tried the web editor, but from what I understand, it generates a server side application that is basically a headless Eclipse. If you want to learn how to write textual languages with good tool support, you could start following a couple of tutorials on Xtext and then jump to this book. These are general programming languages (GPL)that are used for any number of purposes to solve any number of problems. Imagine all sorts of simulators, debuggers, and tools to analyze code coverage. Domain-specific languages As program­mers, the idea of language-oriented program­ming may be new. However, some DSLs become widely used, and you probably already know some of them. Volume II explains how to use the build framework to define complex building configurations, and it gives you an overview of all the different kinds of testing you may want to use for your languages. Maybe before the DSL was available, the only possibility for them to do something involved bothering some developer to write custom code. Want to see what it looks like? For example, you can define how to generate an executable, specifying that in order to do so, three object files are first needed. Watch the video. It will be a good way to invest your time. The goal here is to build a language, with tool support, while keeping the effort reasonable. The same thing applies to programming: some problems are better solved with a specific language, for the reasons we are about to explore. If you think about it, this is the case also for all the graphical languages: you see nice pictures, you drag them around, connect lines, and in the end the editor saves some obscure format, not the nice pictures you see on the screen. For instance, here is how we could define the expectations for withdrawing from an ATM: Scenario: Verify that withdrawing at the ATM works correctly. Most of the people I have worked with DSLs as a key differentiator that helps them increase productivity by 10-20 times, reducing time-to-market and feedback cycles, increasing the longevity of their business logic, and much more. Generally, non-developers do not have the analytical skill to formalize a problem, but they can still read it and understand it, if it is written in a DSL that uses a lingo familiar with the user. This example does not solve any domain-specific domain. You can't write all programs with a DSL like with a general (low-level) programming language. It is also possible to start at the other end: first, you write your scenarios, as you want, trying to capture the requirements, and only later developers map each command to a corresponding function in a GPL. If you are serious about learning DSLs, here is a list of books you could look into. Domain-Specific Modeling: 20 Examples 2. And of course, they are thoughtful and well explained, as you would expect from Martin Fowler. So, here I’m going to start with an example to demonstrate the different forms a … To me, the keys as a DSL designer in this case are being humble and listening. DSLs are small languages, focused on a particular aspect of a software system. When there are errors, the errors are specific to the domain, so they are easier to understand. At this point, you should have some understanding of what a DSL can look like and can be used for. The domain-specific language follows the constraints and rules of the domain, guiding engineers to create correct, consistent and complete specifications. This is vital, but in addition to this, you can significantly increase the productivity of your users by building first-class tool support. Kind of stuff you need to communicate with doctors to understand the interpreter processing DSL code can be easy learn... 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