Re: GDP: Rhythms: add-grace-property

[Trevor Daniels]

Jonathan Kulp wrote Monday, August 11, 2008 11:19 PM

> 1. The "add-grace-property" example currently appearing in NR does not 
> work anymore. --#(add-grace-property 'Voice 'Stem 'direction '())  It 
> needs to be removed or changed

Correct.  Have you investigated whether other properties can
be changed in this way?  For example, try this:

   #(add-grace-property 'Voice 'NoteHead 'color #'red)

(Note that the #' are required here, as the value for color must be a list)


> 2. The way to accomplish the same thing is to use the new 
> remove-grace-property or Neil's ly:stem::calc-direction instead of '() 
> as the direction argument. I got Neil's solution to work but haven't 
> grabbed the new file from git to try Carl's.  Will do that tonight.

I think the remove-grace-property function is best, but perhaps you
should check it works correctly.  For example, try stacking a few
properties and clearing one or two of them in the middle.

> So, the question is whether it's worth introducing add-grace-property 
> and/or remove-grace-property at that point in NR, since it already shows 
> how to alter stem direction using \stemDown in a different example right 
> before it.

The previous example shows how to change a single grace note.
Because this has to be placed within the \grace expression it must
be repeated every time.  The key thing about add-grace-property
is that it applies to -all- grace notes which follow.

>  Is it sufficiently abnormal that it should belong to a 
> snippet instead of appearing in the main text?  Should I create an 
> example that works and then move it to the @snippets area?  This 
> question is probably for Carl :)

I don't feel strongly about this.  A snippet would be fine, perhaps
containing a few different settings to show its generality, and to
demonstrate how it affects all grace notes.  It also need to show
how remove-grace-property works. 

> Jon

Trevor