Anyone else had a chance to read this yet?

Here is the deck, and the presentation was taped, so as soon as I get the URL I’ll post a link to it.

In the next couple of months expect a series of postings regarding Domain Specific Languages in Groovy. They’ll be designed to flesh out the three article series I’ll be writing for GroovyMag. Also expect various postings on Groovy and Grails development, from simple tips and techniques to some funky ANTLR preprocessing stuff and some explorations of AST transformations in Groovy 1.7. I’ll probably also include ancillary technologies like some advanced thoughts on using git and my experiences working with Hudson for CI with Grails projects.

Oh, and there will also be some stuff on Gaelyk – really looking forward to playing with that.

So keep an eye on http://gettinggroovy.com – or just watch for the aggregated posts at the awesome http://groovyblogs.org – that’s where I follow all of my favorite Groovy/Grails blogs.

I’ve reworked the deck a lot from the Sydney presentation, with some more examples and a sense of flowing from an API through internal DSLs to various external DSL approaches if and when they make sense. I also briefly covered a wider range of additional considerations – discussing briefly documentation, error handling and IDE support for your DSLs as well as testing and evolution. I also made it clearer that it wasn’t primarily a presentation on the details of getting rid of parentheses and commas to increase semantic density in Groovy as Guillaume Laforge has already nailed that material. This is really a focus on the wider engineering concepts that arise when designing and developing DSLs.

I’m liking the presentation now, although I think I *will* add a couple more slides with examples round the syntax as I found myself talking about things like categories and ExpandoMetaClasses and even the ANTLR preprocessing hooks and a slide or two would probably have helped comprehensibility – especially as I was just shooting through the syntactic materially really quickly.

I just wanted to thank everyone for coming out and in particular Mark Pollack for arranging the location, food and beer and actively participating in a meetup about a technology he doesn’t get to actively develop in!

Here’s the deck.

On another note, we’re looking to put together another meetup next month. If anyone has any ideas on a topic they’d like to see covered or would like to present on, suggest a topic!

Peter Ledbrook will also be giving a presentation on the upcoming features in 1.3, so I’m looking forward to catching that!

Looking forward to meeting old friends and new in the Groovy/Grails community in London. And if you’re interested in DSLs even if you don’t do a lot of work in Groovy, come along and check out the preso – it’s relevant for anyone interesting in adding DSLs to the mix of techniques they use when developing apps.

Here’s the summary:

What are some practical uses for Domain Specific Languages? And how do you go about designing DSLs, implementing them in Groovy, creating tests for your models and evolving the structure of the languages over time? In this fast paced session we’ll look at a real world Groovy DSL, how it was designed and implemented, the testing strategies employed and the options for evolving the structure (grammar) of the DSL. If you’ve built DSLs but want to go further, or if you’ve still not figured out how a DSL might help you to build better, more maintainable apps more quickly and easily, come along and learn more about creating practical, maintainable DSLs for your projects.

It is based on a talk I recently gave in Sydney and will be presenting in New York next week. Hopefully I’ll see you in London!

Update: registration now available . . .

The issue also includes a piece on contract oriented programming by Andre Steingress, Hamlet D’Arcy continuing his series on Lean development using Groovy, Bjoern Wilmsmann on Natural Language Processing in Groovy, a detailed look at Java Strings in Groovy by Kirsten Schwark and Dave Kleins regular plugin corner reminding us of the power of the Quartz plugin.

Why not check it out? If you’re a subscriber, just download your copy. If not, why not give it a shot for just $5? If you’re really not sure, use the code “peterbell” and you can get one issue for free to try it out. I really like that we have a monthly magazine specifically for the Groovy community that is more timely than books, but better curated and more in-depth than most blog postings. Let’s support it so it continues to grow and become an increasingly valuable resource for the community as we grow.

It was the first time I had given the presentation, but despite rewriting it about 4 hours before the presentation and jetlag (I’d just landed in Sydney from New York that morning) the presentation was well received. The goal of the presentation was to put context around the process of working with internal DSLs by examining the uses for DSLs, approaches to designing of DSLs, the differences between internal and external DSLs and lifecycle concerns such as testing and evolution. I think it provided a good introduction to the material.

For the next presentation, I want to add a little more detail on good language design choices, testing and evolution and I’d also like to add an end to end example I can evolve and a little more coverage of the language features available in Groovy for implementing internal DSLs, but I feel like it was a good first shot at presenting the material. DSLs/DSM is a huge topic and it’s always difficult to figure out exactly what material will help people to do the best job of designing DSLs and to fit it into a one hour slot.

Thanks for everyone who came and supported the event. Particular thanks to Paul King who flew down from Brisbane. He also kindly shared a bunch of ideas based on his DSL Groovy presentations that I look forward to incorporating into the next cut of this preso.  I enjoyed a great evening discussing everything from DSL design through GPars to ideas on new features for 1.8 and beyond – it was great to spend some more time with one of the team that provide us with such a cool language to work with!

The answer for me is to do what I’ve done in every other domain I’ve been involved with – get involved with the community. (I’m relatively new to Groovy and Grails, but I’m pretty involved in the Domain Specific Modeling and ColdFusion communities). Helping out on the mailing lists and contributing to plugins is a great way to get started, but it’s hard to beat the face to face interactions you get at user groups and (especially) at conferences. That’s why I decided to go to gr8 in the US, am presenting on DSLs in Sydney, New York and (hopefully) London this month, and will be attending gr8 in Copenhagen next month (even though I can only manage a day as I’m presenting at the BCS SPA conference on DSL design on the Wednesday).

I was lucky enough to attend Gr8 last year. It was an amazing chance to get to know many of the key developers in the community, to build up a set of resources so that if we do ever get stuck on a technical challenge we can get on IM and often get an answer or idea from someone in minutes instead of hours or days of futzing around. Why do I mention this? Well, Gr8 conference is the only dedicated Groovy and Grails conference in Europe and a great opportunity to learn about a whole range of projects within the Groovy ecosystem – including Grails, Griffon, Spock, Gradle and Gaelyk. More than that, it’s a chance to meet up with other developers dealing with the same adoption, implementation and technical challenges that you work with every time you develop a Groovy based project.

There is still time to register for the conference, so think about how much it costs when you’re stuck on a project for a day trying to figure things out, and I hope you can get a cheap flight, a modest hotel and a ticket to the conference into the budget. It’s not cheap, especially with the market right now, but the only thing more expensive than going to the conference? Working on a project in Groovy/Grails and being stuck *not* having gone to the conference for the amazing technical content and great networking.

Hope to see you there! (If you see me, please say “hi”) – I’ll be the jetlagged one drinking too much Red Bull