Re: indentation via text or overlay property?

[Kevin Rodgers]

Stefan Monnier wrote:

> > Cool!  But since those spaces are displayed instead of the original text
> > (not in addition to it), I don't see how to use that to
> > implement indentation.
>
> You might want to put that property on an overlay (of size 0), then.


Good idea, especially because I want to avoid modifying the buffer.  But I'm
having problems getting overlays of size 0 to work.  Trying things out manually
with M-:, I've only gotten the desired effect once.  I'm trying things like:

(let ((lbp (line-beginning-position)))
  (overlay-put (make-overlay lbp lbp)
               'display '(space :align-to 4)))

(let ((lbp (line-beginning-position)))
  (overlay-put (make-overlay lbp lbp)
               'string-before (make-string 4 ? )))

> > Thanks for the pointers.  Is the correct way to test for this feature:
> >         (>= emacs-major-version 21)
>
> I think (featurep 'text-properties 'display) is better.

| Debugger entered--Lisp error: (wrong-number-of-arguments #<subr featurep> 2)


--
<a href="mailto:&lt;kevin.rodgers&#64;ihs.com&gt;";>Kevin Rodgers</a>