Compile-time AST manipulation API

[0ffh]

I wonder: There are quite a few requests floating
around that would require changes to the D language.
If the D language is going to be changed, why not go all
the way and make the change to end all change requests:
A small compile-time API for AST walking and manipulation.
I don't just mean macros, but full scale metaprogramming.
It would even be possible to do refactoring and convert
the AST back to source from within the language.
The only problem I really see is that it would require the
AST structure to be part of the language specification.

regards, frank