Released 2005 out of band from VS2005 Notice the lack of whitespacing?
If this were linq to sql(or EF) the expression part would be easier to see/discuss Late binding, questionable practices, and much more!
Metaprogramming by brandon
Metaprogramming in .NET By Brandon D’Imperiohttp://imaginarydevelopment.blogspot.com
What is it?• Metaprogramming is most easily defined as beside-programming or after-programming – Late-binding – Runtime compilation – Code generation
Where is it?• You’ve already seen and used it, most likely – Microsoft • System.Reflection • CodeDom • Emit • T4 • Dynamic Language Runtime (DLR, dynamic keyword) Generating Intermediate Language (IL) with Expression Trees • Roslyn (compiler as a service) • Enterprise Library’s Policy Injection block • Generics – Aspect Oriented Programming
Why?• DRY – Don’t repeat yourself – don’t duplicate authority – Boiler-plate code – Simplify manual coding hand work • Update the entire system at a single point rather than search and find by hand• Lack of higher order functions• Make parts of the application update or adjust based on each other at the click of a button
Final words• “metaprogramming is all about making software simpler and reusable. However, rather than depending strictly on language features to reduce code complexity or to increase reusability, metaprogramming achieves those goals through a variety of libraries and coding techniques”• “For the most part however, metaprogramming is a set of language independent skills.”• “As perceived complexity from the end users standpoint goes down, internal complexity of the design often goes up. Complexity reduction when metaprogramming follows the same rules. To achieve simplicity on the outside, the code on the inside of a metaprogramming-enabled component typically takes on some added Responsibilities”
More about me• http://imaginarydevelopment.blogspot.com• https://www.ohloh.net/accounts/Maslow• http://stackoverflow.com/users/57883/maslo w
Appendix• Roslyn Code source – http://code.msdn.microsoft.com/Implementing-a-Code- Action-28579fb1• Many of my T4’s available – http://ideone.com/imaginarydevelopment/t4• Emit Full source – http://breusable.codeplex.com/SourceControl /changeset/view/92288#1863265• AOP – was a little deeper than I thought we would have time for – http://www.sharpcrafters.com/ – http://www.mono-project.com/Cecil