Re: stepping down as project manager

[Reinhold Kainhofer]

On 2012-10-14 01:07, Joseph Rushton Wakeling wrote:
> On 10/13/2012 11:44 PM, David Kastrup wrote:
> > \once creates a one-time-step temporary change, \temporary an
> > unterminated temporary change which can be terminated element-wise with
> > \revert or, again using a converter, en bloc from the original overrides
> > with \undo.
>
> Forgive me for coming into this without the background, but what's the
> difference between \temporary and the existing \override?

\temporary\override would work the way you probably expect \override to 
work now:
It sets the grob property to a new value and keeps the old value stored 
so that after \revert the property takes the old value it had before the 
\temporary\override.

The actual problem is that \override currently CLEARS (i.e. reverts) the 
current value before setting the new one, so that the old value is not 
stored anywhere any more, and a \revert thus reverts to the default value.

As an example, let's look at the following code. What color would you 
expect the final "b" to have? red? (because the \revert clears the 
previous override to blue, right?)

\version "2.16.0"

\relative c' {
  c4
  \override NoteHead #'color = #red
  f
  \override NoteHead #'color = #blue
  g
  \revert NoteHead #'color
  b
}

In reality, the \revert does not revert the override, but completely 
clear the value to the black default. Currently, there is no way to 
temporarily change a property and then change it back to its previous 
value (except for \once\override, which only works for one timestep).

In fact, \override and \revert are currently misnamed, they work more 
like \set and \unset.

Cheers,
Reinhold

--
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Reinhold Kainhofer, address@hidden, http://www.kainhofer.com
 * Financial & Actuarial Math., Vienna Univ. of Technology, Austria
 * http://www.fam.tuwien.ac.at/, DVR: 0005886
 * Edition Kainhofer, Music Publisher, http://www.edition-kainhofer.com