Re: Why token are numbered from 258?

[Peng Yu]

> 256 is the error token, and 257 is the undef token (when we receive unknown 
> tokens from yylex).
>
> 256 is mandated by POSIX :
>
> https://pubs.opengroup.org/onlinepubs/007904875/utilities/yacc.html
>
> > The token error shall be reserved for error handling. The name error can be 
> > used in grammar rules. It indicates places where the parser can recover 
> > from a syntax error. The default value of error shall be 256. Its value can 
> > be changed using a %token declaration. The lexical analyzer should not 
> > return the value of error.
>
> It seems to say that we should be able to change the value with `%token error 
> 2400`, but we don't support that.  (checking...)  OMG, we do support it!  New 
> test case...

OK. I find 256. But 257 is not found anywhere in y.tab.c or y.tab.h?

y.tab.c:#define YYERRCODE       256

Also, YYERRCODE is not found in the manual, should it be mentioned there?

-- 
Regards,
Peng