I have a small proposal that I'd like to float.
In building a parse tree for a complex language, it's very helpful
to identify which nodes correspond to which productions in the
grammar. Bison already has internal identifiers for each non-
terminal and carries around ASCII strings for each in yytname[].
What I'd dearly love to see is the ability (probably as an option)
to export these symbols into y.tab.h, preferably as part of an enum.
It's possible to generate this by hand, but as it's not
automatically maintained today, any significant change in the
grammar requires a manual update of the symbols. This is Not Fun.