I presented at the Philly Code Camp on 11 October 2008 for a group of about 20 developers. Thanks to all who came out to listen to my presentation. And thanks especially to Don Demsak (donxml) for attending and really helping me to shape the talk. Don added a lot of anecdotal information that I would not have included on my own. It was a very fluid discussion with lots of give and take. When I give this talk again at the Raleigh Code Camp in November 2008, the folks who attend will benefit from what happened in Philly.
The gist of this presentation is that it's possible to mix the Dynamic Language Runtime (DLR) into statically-typed, early-bound languages like C# to make them much more flexible. In this talk, I demonstrated how a ShoppingCart being filled with Products can adjust discount rates based on marketing rules written in an external Domain Specific Language (DSL). In this case, my DSL was really just Python. I chose to use Python because the syntax is so simple and clean. It's so light, it doesn't get in the way. It's not a real DSL, of course, but by injecting .NET objects into a ScriptScope on a ScriptRuntime (all DLR hosting terms), the Python syntax acting on those injected types looks an awful lot like a language for managing product discounts.
The few slides I had and the source code are linked below. For this code, I used IronPython 2.0 Beta 5. You will need to download and install IronPython to compile the code.
MixingStaticAndDynamicDotNETLanguages20081011.pptx (91.66 kb)
MixingStaticAndDynamicDotNetLanguages20081011.zip (16.65 kb)