Customizing display of tokens(%print?)

[Frans Englich]

Hello,

When Bison prints error messages for symbols, it doesn't take into account 
possible semantic values. For instance, it says "unexpected <literal>, 
expected foo".

What would be much more helpful is if it printed the semantic values instead. 
For instance, "123" instead of "<literal>" and "myVariable" instead of 
"<identifier>".

I first thought that the %print-feature, mysteriously used in examples but not 
documented, did this. But it's a whole feature for the purpose of 
improving... /debug/ output?

Is there any way to register code for printing helpful token descriptions?

(Yes, there is %token name "string" when it is known statically.)


Cheers,

                Frans