David Kastrup <[email protected]> writes: > "Joel E. Denny" <[email protected]> writes:
[...] >>> I have not checked that the enhancement for reducing rules with more >>> than one token does actually work. It seems like an obvious change, >>> but I don't really understand Bison enough to be sure. >> >> Does this mean you haven't found need for that enhancement then? > > Up to now, I have been just doing basic tests and trying to figure out > why I could not get stuff to work at all. It seems one should always > be able to program around the missing enhancement by creating > one-element rule aliases to all multi-element rules one wants to back > up. Update: no, that does not work, since backing up only moves backwards one reduction, so putting an alias in between will not help. It would seem, however, that YYPOPSTACK (yylen) is the wrong thing to do: when the action is executed, apparently the stack has already been reduced to have one lefthand value left. So YYPOPSTACK (1) seems correct regardless of the value of yylen (possibly excepting yylen==0 though I don't think this can ever occur). -- David Kastrup
