[antlr-interest] Faster expression parsing for ANTLR

[Gavin Lambert]

At 22:18 18/12/2008, Zenzike wrote:
 >I thought about that, but I wasn't sure it would work -- 
wouldn't
 >the scope be shared between the recursive calls to e[]?
[...]
 >If the parameter p were scoped, rather than passed, then we 
forget
 >the call-tree that gets us to our current position don't we?
 >My understanding might be wrong -- I thought scoped in the 
grammar
 >became static variables in the target language, is that true?

Yes, but they're represented as stacks rather than discrete 
values.  So recursive usage of them is safe.  (Have a look at the 
reference for $ values to see the syntax to refer to earlier items 
in the stack.)