Re: yytname woes

On Sunday, November 12, 2023 6:18:30 PM CET James K. Lowden wrote:
> On Mon, 13 Nov 2023 12:33:57 +0100
> Christian Schoenebeck <[email protected]> wrote:
>=20
> > > When I look up #899, NOT, I get "NOT".  But when I look up #900,
> > > NE, I get "'<'" because that's the next element in yytname (900 -
> > > 255).
> > [...]
> >=20
> > Are you aware that yytname[] is indexed by "symbol-number", not by
> > "token- number", as it contains terminals and non-terminals?
>=20
> That's interesting.  No, I'm not.  Respectfully, how could I be? =20
>=20
> The term "symbol-number" does not appear in the Bison info manual.  The
> %token-table directive says
>=20
> 	"?yytname[I]? is the name of the token whose internal
> 	 Bison token code is I.'=20
>=20
> You tell me: what is a "Bison token code"?

Look, I am not judging how well Bison is documented or what good/bad
terminology Bison authors chose. It's not my business. You asked a question
and I just read the auto generated parser code, which says:

  /* YYTNAME[SYMBOL-NUM] -- String name of the symbol SYMBOL-NUM.
     First, the terminals, then, starting at YYNTOKENS, nonterminals.  */
  static const char *const yytname[] =3D
  {
    ...
  }

Looking further down in the auto generated parser code I see:

  /* YYTRANSLATE(TOKEN-NUM) -- Symbol number corresponding to TOKEN-NUM
     as returned by yylex, with out-of-bounds checking.  */
  #define YYTRANSLATE(YYX)                                                \
    ((unsigned) (YYX) <=3D YYMAXUTOK ? yytranslate[YYX] : YYUNDEFTOK)

  /* YYTRANSLATE[TOKEN-NUM] -- Symbol number corresponding to TOKEN-NUM
     as returned by yylex.  */
  static const yytype_uint8 yytranslate[] =3D
  {
   ...
  }

And from the values in yytranslate[] it seems this is just the missing brick
you were searching for to accomplish your to task. Right?

As a side note: there is probably no other person on this list helping out
people with questions as often as Hans =C5berg does. #tone

/Christian