Re: Location tracking (Was: Redifining yyltype)

[Hans Aberg]

At 22:06 +0200 2004/04/12, Henrik Sorensen wrote:
>AFAICT, the locations are only used in the YYLLOC_DEFAULT macro, and then
>as a
>dummy parameter to yysymprint. It would of course be quite nice to include
>the location information as well. Beside hacking the skeleton files,

Bison was changed to use M4 in order to facilitate such hacking.

>...is there
>any official way, I can redefine yysymprint or the macro YYDSYMPRINT?

Location is largely unsupported, currently, so you are probably on your
own. Bison used to define the location as the region of the grammar symbol
where the error occurred. A more practical approach is probably to define
it as the region of the erroneous token, plus the line where the error was
detected.

>Are there any particuliar reasons for concern when using the location
>tracking
>?
>Or is nobody actually using this feature ?

In the Bug-Bison list, thread "GLR parsers and locations " starting
2003-06-05, Frank Heckenbach <address@hidden> asked some location tracking
questions. So perhaps he is using it.

  Hans Aberg