Re: null markup

[Graham Percival]

On 27-Aug-05, at 1:00 PM, Han-Wen Nienhuys wrote:

> Mats Bengtsson wrote:
> > As far as I can understand, a \hspace #0 gives a markup that is
> > 0pt wide but has a height that is the total height (i.e. the depth + 
> > the
> > height) of the characters in the font. That's the only way I can 
> > explain
> > what happens in your example. However, I'm not sure if that's a good
> > behaviour for \null in general. Consider for example the difference
> > between the two boxes in
> > \markup{\box \column { A \line {a \hspace #0.0 } }
> >         \box \column { A \line {a \null} } }
> > I think the current implementation of \null behaves more intuitively.
> > On the other hand, the alignment issues of markups in general are far
> > from clear.
>
> There is a \strut command to do this, but last time I looked it was 
> broken.

\strut certainly doesn't appear to do anything now.  What is is supposed
to do?  If it's the same thing as \hspace #0 or #1, then wouldn't it 
just be

(def-markup-command (strut layout props amount) (number?)
  (if (> amount 0)
      (ly:make-stencil "" (cons 0 0) '(-1 . 1))
      (ly:make-stencil "" (cons 0 0) '(-1 . 1))))

(tweaked hspace)
... hey, how does hspace #0 do anything?  if amount=0, then surely
\hspace shouldn't do anything?

  (if (> amount 0)
      (ly:make-stencil "" (cons 0 amount) '(-1 . 1))
      (ly:make-stencil "" (cons amount amount) '(-1 . 1))))


- Graham