Re: [bug-bison] Bug in string-valued terminals

[Joel E. Denny]

Hi Tom,

I've added help-bison.  Maybe someone there will know more.

On Wed, 29 Dec 2010, Tom Roberts wrote:

> Ok. I decided to not use yytoknum[], as it is undocumented and also requires a
> funky "#define YYPRINT". Here is the code I am using inside yylex():

>                 for(int i=0; i<YYNTOKENS; ++i) {
>                         if(yytname[i][0] != '"') continue;
>                         string name(yytname[i]+1);
>                         name.erase(name.size()-1,1);
>                         for(int j=YYMAXUTOK; j>0; --j) {
>                                 if(yytranslate[j] == i) {
>                                         keyword[name] = j;
>                                         break;

Isn't your inner loop sufficient?  The body could just translate and index 
into yytname.

In any case, YYMAXUTOK and yytranslate are not documented for users 
either.

Again, it would be great if someone could recall how %token-table and the 
yytname table it generates were originally intended to be used.  The 
trouble is that yytname indices are internal token numbers, but there 
seems to be no mechanism that is documented for the Bison user to 
translate internal token numbers to user token numbers (which are the 
token numbers returned by yylex).  How then is yytname useful?