Re: Make \shiftOff an assertive \override, not a \revert (issue 190500043 by address@hidden)

[Keith OHara]

On Sun, 10 May 2015 11:02:21 -0700, <address@hidden> wrote:

> It's not clear why you are now mixing in variants of conversion rules
> for issue 4372.

I noticed that my rule made the same \b mistake as yours, and they are right 
next to each other, and I thought it was an easy fix, so I tried fixing both at 
once.

> But at any rate I think you need to explain why you think that you want
> a convert-ly rule to retain behavior that you consider
> a) to not correspond to the documentation or expected behavior
> b) to not deserve a command of its own
> c) you do not consider worth documenting separately
> d) which requires explicit protection of the documentation from
> conversion

It was hard to decide whether to have the convert-ly rule or not for \shiftOff.

For existing music that used the old shiftOff = \revert 
NoteColumn.horizontal-shift,
the replacement \undo\shiftOn  has the same expansion.

I searched for uses of \shiftOff and found that Urs Metzger has a few pieces on 
mutopiaproject that use \shiftOn \shiftOff pairs as if they were a set/revert 
pair.  The convert-ly rule doesn't help for those examples, though, because 
they have hand-adjusted shifts in the other voices.

The \revert version generated "too many clashing notecolumns" warnings, which is now 
"need a \shiftXxx", and I thought it a bit safer to keep a warning.

The manuals did not use \shiftOff in LilyPond code where it had any effect, but 
only talked about its desired effect in the text.  Thus the manuals should not 
get any convert-ly rule.


If you revert the convert-ly rule, it would be more tidy if you also reverse 
its changes in
'Documentation/learning/fundamental.itely' and 
'Documentation/fr/learning/fundamental.itely'
Only three lines each file.   :%s/\\undo\\shiftOn/\\shiftOff/g