Why "Polyglot Programming" or "Do It Yourself Programming Languages" or "Language Oriented Programming" sucks?

Last year we saw the launch of a new Web programming language Dart - Structured Web Programming from Google. A very interesting approach to support web application development. Not so long after Go, Groovy, Ruby, Scala, << Name your DSL here >>; we see Dart. Is it a good thing to have at least one programming language to solve one problem? The answer is, like we already know, it depends.

Stay Away From “Do it Yourself”

It is your choice as to if you will try to do things yourself or allow the truly seasoned professionals to help out. Some decide that they are going to try to go it alone when they are programming something new, but this often ends up in a less than desirable place. It may even be more expensive than just hiring an expert who can help you get it programmed for you in the first place.

Most people do not go it alone with the vast majority of important services in their life, so why should they ever attempt to do so when they are looking at how to create a website? It is best to avoid making this mistake, and just try to make some progress towards your goals by hiring people who truly know how to help you make the progress that you need to make.

Some important backgrounds you should know about the multi-programming language paradigm are the following:

1. You can read Martin Fowler's article about language-oriented programming with language workbenches which enables you to write small programming languages easily. In this article I see everyone writing their small language, everywhere. In this concept, we see DSL (Domain Specific Language) as the future of our programming activities. Source: http://martinfowler.com/articles/languageWorkbench.html

2. Neal Ford talked about Polyglot Programming, combining multiple programming languages in application development. Later Mr. Fowler added this paradigm with Polyglot Persistence, using different types of databases within one application. Source: http://memeagora.blogspot.com/2006/12/polyglot-programming.html and http://martinfowler.com/bliki/PolyglotPersistence.html

Since 2006 I already discussed and collected some experiences in multi programming language paradigm:

1. I remember a “hot” discussion in 2006 with Sebastian Meyen, chief editor of JavaMagazin Germany, also the biggest organizor of Java Conference JAX. We agreed to see the future of programming in a multi-language paradigm concept. I also said that all those languages will be based on Java VM. I also told him that one day SAP will move ABAP as a language that can be run within the Java VM, so just another language within the Java environment, with no two different personalities anymore. Today we see the beginning of this in the project called Caffeine ABAP. Source: https://cw.sdn.sap.com/cw/groups/caffeine

2. Also in 2006 I had a project in which we also used different kinds of languages and also created our own DSL: Java for the most implementation stuff UML for the design of the business objects. We generate a lot of things using the concept of MDA (Model Driven Architecture) Groovy for a lot of things, especially for writing unit tests Based on ANTLR we create our own DSL for some aspects of the application It was really exciting and we had some very good programmers in the project. The result was a very nice and flexible product, just as what we expected at the beginning of the project. Please read this article in the German language for more information: http://www.sigs.de/publications/os/2009/02/dewanto_egger_OS_02_09.pdf

So after all those nice things about the multi-language paradigm, I told you, why does this suck at the end? Here are some reasons from my point of view:

1. As typical in application development the problem comes first in the maintenance phase after all the capable programmers leave the project. Did you, programming language creators ever try to teach a new programming language to a “normal”, 9 till 5 programmers? I’m not talking about 9 (am) till 9 (pm) programmers who love to learn new languages. It is definitely tough to be proficient in one programming language. This is comparable with the languages we speak every day. I’m not a native English speaker, so I’m quite sure that I made a lot of syntax and grammar errors in this article. It is possible to be able to speak three or four languages perfectly but this is an exception.

2. Did you ever try to maintain a big Struts web application with AJAX? Just try to add functionality and you will end up creating and editing a lot of files: Action and Form files, Struts XML configuration files, JavaScript files with JSON, and also HTML or JSP files. Can you imagine adding Groovy, Scala, and Dart additionally into that web app? The complexity of such a project is very high.

3. Creating a new programming language means that you also have to build the environment for it. Good IDE, good documentation, good community support, a clear roadmap, and backward compatibility are some points to be done. Groovy is a bad example of this. In the early version of this language, the editor for Eclipse was really bad. After a while, they improved the editor but they made a lot of basic changes in the language so your old groovy applications do not work anymore. You are punished if you update to the new version. This never happens to Java. You still can compile Java 1.1 applications with Java 6 compiler.

4. Before you are creating your own DSL with e.g. ANTLR ask those language Gurus first, how hard it is to maintain a programming language for the long term. Before you discuss with them don’t ever create your own DSL. Especially if you are working for SME (Small and Medium-sized Enterprise). With a small team and small budget, you will never ever maintain your own language decently.

So in year 2012, six years after my support to Polyglot Programming, I hope to see following things happen:

1. One language for all aspects in one application is the best concept ever. I name this as “One for All Programming Language paradigm”. Just like we don’t use English as a technical language, German as a literate language, and Indonesian as a community language, to be able to communicate internationally with each other we just use English pragmatically for all aspects of our life. In Germany, you need to speak German in all aspects to be able to communicate with others. My best solution so far is Java + XML, that’s it, no more, no less. No mixing with Groovy, Dart, Ruby, Scala, <> in one application. Especially if you are working as a contractor, please don’t try to use all those languages just for a small Java web application. I don’t say that you should not use the other languages at all. The only thing which is important is not to mix those languages in one application. In SME you may also want to use just one programming language for all your applications.

2. Concept like GWT (Java to JavaScript compiler) or XMLC (XML compiler which compiles XML, HTML to Java classes) is great. You can work just in plain Java. Guice with all Java and no XML is also a great solution (I know that SpringFramework is also doing this with Annotations). Android is great because it uses Java as its application programming language.

In conclusion, I can only hope to see more such pure and plain Java solutions in 2012!