[antlr-interest] executing actions during backtrack
Jeff Barnes
Jeff.Barnes at codesic.com
Thu May 11 12:13:03 PDT 2006
Martin sez:
Sorry, but that sounds a lot like implementing a database, but at all
like implementing a parser generator, at least to me. And you didn't
even start about all the concurrency issues with the log ;-)
Jeff sez:
Sounds like an undo stack to me. Yeah, some databases do it that way, Oracle in particular. But the GOF patterns (Command and Memento) are more general than that.
The technical problem with this and the new ground that Ter is breaking, as I understand, is having a DFA-based LL(*) parser. Even more expressive and therefore difficult would be to implement NFA with an undo stack.
Just curious, why would there be concurrency issues? The issue to me would be solved at the same time as a concurrency issue with a shared input stream.
Regards,
Jeff
More information about the antlr-interest
mailing list