custom AST library

[Alex_Dovhal]

Hi,

I'm currently making some custom AST parser for D :

http://pastebin.com/1hmnTUbY -- AST Parser

http://pastebin.com/ZRc5be1p -- Sum example

Right now both lexer and syntax parser are just awfull and they don't work 
in CTFE because of class usage. But example looks rather interesting, with 
such approach (if it works) one can create full list comprehension like 
python's one or MS LINQ for C# system as user library.

I tried to change class to struct, but failed :-( Any ideas how to make it 
work in CTFE ?