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

[Hans Aberg]

At 12:12 +0200 2002/07/09, Akim Demaille wrote:
>And, yes, as answered by Hans, $ = EOF.

Strictly speaking it is "end of token stream", not EOF = "end of file".

>I'm fine with renaming $ to something else.  BYacc names it `$end'.
>Avoiding `$eof' is not a bad idea, given that we may be scanning a
>string.

The yytaname table starts:

/* YYTNAME[TOKEN_NUM] -- String name of the token TOKEN_NUM. */
static const char *const yytname[] =
{
  "$", "error", "$undefined.", ...
};

Here, "error" has a normal name, whereas there are two corny names "$",
"error", "$undefined.". These names are not used for anything but to write
error messages. I think one could take some more descriptive, better
looking, userfriendly names, like
  "end-token"
  "undefined"
  "undefined token"

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

  Hans Aberg