Good examples for dmd.frontend?

[Doc Andrew via Digitalmars-d-learn]

Hello,
  I'm doing some experiments trying to use the DMD front-end as a 
library to generate code (Why3ML) that can be used in a formal 
verification tool. However, documentation is a little sparse. 
I've looked through the examples in dmd/src/examples, and they 
were a fine starting point but now I'm getting to the point where 
I need to snag function arguments, types, and contracts out of 
the AST.

  Can anybody point me to some good examples of other projects 
that use the DMD front-end that I might be able to reference?

Thanks,
  Doc