Re: [O] [RFC] [PATCH] Changes to Tag groups - allow nesting and regexps

[Gustav Wikström]

Hi, see below

> >
> > * lisp/org-agenda.el (org-agenda-filter-make-matcher-tag-exp): Deal with
> >   the case when the user provided an empty string to filter or exclude
> >   rows from the agenda.
> 
> Please provide a reference to the discussion that lead to this patch.

The reference being the subject-line and date of the mail from sgeorgii?

> 
> >        (let* ((tag (substring x 1))
> > -        (isregexp (and (equal "{" (substring tag 0 1))
> > +        (isemptystring (string= "" tag))
> > +        (isregexp (and (not isemptystring)
> > +                       (equal "{" (substring tag 0 1))
> >                         (equal "}" (substring tag -1))))
> >          regexp)
> >     (cond
> >      (isregexp
> >       (setq regexp (substring tag 1 -1))
> >       (setq f1 (list 'org-match-any-p regexp 'tags)))
> > +    (isemptystring
> > +     (setq f1 '(not tags)))
> >      (t
> >       (setq f1 (list 'member (downcase tag) 'tags))))
> >     (when (eq op ?-)
> 
> Nitpick time:
> 
> You don't need isemptystring if it is the first branch in cond
> 
>   (cond
>    ((string= "" tag) (setq f1 '(not tags)))
>    (isregexp ...)
>    (t ...))
> 
> Obviously, in that case, you don't need to change isregexp at all.

Hmm, since the error was thrown when trying to look at indexes outside of the 
string in (substring ... ), I don't see how isregexp can be left as is. We have 
to make sure the substring-code is not evaluated if the tag is empty. What am I 
missing? 

> 
> 
> Regards,
> 
> --
> Nicolas Goaziou                                                0x80A93738