How much of C# syntax can you use in an Expression shape?

In case you were wondering why you are not able to do certain operations in the BizTalk Expression shape within an Orchestration, here is the answer:

How much of C# syntax can you use in an Expression shape?

The bottom line is that the language under the hood is not C#, but is XLANG/S which cannot support certain tasty morsels that C# developers know and love (for, foreach, (++,--), etc. Big frowny face for that one!

Here's another link that goes into even more detail:

http://geekswithblogs.net/cyoung/articles/3820.aspx