[antlr-interest] Re: Translators Should Use Tree Grammars
micheal_jor
open.zone at virgin.net
Tue Nov 23 01:42:04 PST 2004
--- In antlr-interest at yahoogroups.com, Monty Zukowski <monty at c...> wrote:
> This may have not been very efficient since I was walking and building
> trees for every other rule even though I didn't need to. The building
> far outweighs the walking, and Loring has been addressing that issue
> with his new tree code.
Does a tranforming tree parser (i.e. buildAST=true) really rebuild
every node of the tree it traverses?. Even if no explicit
transformation is specified?. I was under the impression it simply
walked it.
> I agree that pattern-matching with ANTLR grammars is not fun, because
> you do the actual testing in actions or semantic predicates.
You don't have to (do the testing in actions/sem_preds). You could
encode the disambiguating attributes in the tree itself. Messy though.
> The main point is that I still want to specify the order of my
> translations. There are some directions ANTLR could go toward making
> the specification of translations easier, namely pattern matching and
> substitution.
AFAIK, ANTLR's meta-langauge already supports pattern matching (on AST
structure) and substitution in tree parser grammars.
Short of additional passes, can't see how a tool like ANTLR can help
with the ordering issue. Actually, what is the issue with the ordering
of translations?
Micheal
ANTLR/C#
Yahoo! Groups Links
<*> To visit your group on the web, go to:
http://groups.yahoo.com/group/antlr-interest/
<*> To unsubscribe from this group, send an email to:
antlr-interest-unsubscribe at yahoogroups.com
<*> Your use of Yahoo! Groups is subject to:
http://docs.yahoo.com/info/terms/
More information about the antlr-interest
mailing list