Good morning!
I'm a huge fan of this project and I'm using it for several of my small
personal project (hopefully one day I will get to finish and publish one
of them). I use both flex and bison C++ Language Interface (not that it
has anything to do with the feature I'm about to request) and one
feature that is available on Flex that is not on Bison is a macro that
executes just before the rule action is executed. On flex, it is
YY_USER_ACTION
(http://www.gnu.org/software/flex/manual/html_mono/flex.html#SEC14), but
there is no (documented) equivalent for it on Bison. I know there is the
YY_REDUCE_PRINT macro, but it is only for debug purposes, and not meant
(not to say not possible) to be overridden.
The reason for my request is that, as bison generates LR parsers, there
is no way to, for instance, execute an action before a rule is reduced,
only after.
Thanks in advance for the patience to understand my garbled english (as
it is patent, english is not my 1st language). And keep up the good work!
Fernando Ferreira
_______________________________________________
help-bison@gnu.org http://lists.gnu.org/mailman/listinfo/help-bison
