Re: Bison and $ (dollarsign) token at the end

[Akim Demaille]

>>>>> "Hans" == Hans Aberg <address@hidden> writes:

Hans> Here, "error" has a normal name, whereas there are two corny
Hans> names "$", "$undefined.". These names are not used for anything
Hans> but to write error messages. 

And traces (YYDEBUG).

Hans> I think one could take some more descriptive, better looking,
Hans> userfriendly names, like "end-token" "undefined" "undefined
Hans> token"

Hm, I think the point of the $ business is to insist on the fact that
these are internal symbols, not reachable by the user: one cannot use
$ or $undefined in the grammar, while error is allowed.

Hans> Perhaps one should even have macros for these names (say
Hans> YYEND_TOKEN_NAME, YYUNDEFINED_TOKEN_NAME), so that they can be
Hans> changed at will.

This is already the case of $:

%token YYEOF 0 "end of file"

The question is really wrt the internal, out of user name space,
name.