[antlr-interest] "context sensitivity" of tree parsing

[Benjamin Shropshire]

Loring Craymer wrote:
> You have discovered the two possible options--replicate rules or use a state flag--for single pass processing.  There are also cases where it is possible to do something with StringTemplates, and you can  add in a tree walker pass that prunes the subtrees for which you do not want to execute actions.  If you are doing complicated analysis, the extra tree walker pass can be the best solution (and it may turn out not be an extra pass)--it never hurts to simplify.
>
> --Loring
>   
Ironic, this /is/ in an extra pass (build symbol table on pass 1, uses 
symbol table on pass 2). The issue arises because symbols are syntactic 
rather than lexical constructs and the same rule's apply to both the 
syntax of the deceleration and to the syntax of the usage.

Anyway, thanks.