[antlr-interest] figured out how to do tree rewriting

[Terence Parr]

Hi,

I spent some time today and figured out an efficient way to do AST  
construction from tree grammars (completely fresh new tree) and tree  
rewriting where only subtrees from rules with -> rewrites get  
altered.  Very efficient in space if you want to tweak a tree.  Fits  
on 1 blackboard. ;)

Kay arrives on Sunday...he can motivate me to implement this...  and  
finish my v2 to v3 transition for antlr.

Ugh, i have my tenure application to work on too!

Ter