Re: polyphonic shorthand; line-spanner-interface in Hairpin

[Mats Bengtsson]

Kieren MacMillan wrote:
> Hello,
>
> Thanks to Carl's patient help, I've successfully submitted my first 
> patch as a Frog!
> <insert sound of trumpets, throw confetti, etc.>
>
> 1. For my next task, I was thinking of fixing the polyphonic 
> shorthand. Unfortunately, searching the tree for
>   <<
> gives a couple of thousand hits...  ;-)
> Any hints on where that shorthand is defined would be greatly 
> appreciated.
If you look in lily/parser.yy, you will find that a "\\" corresponds to  
E_BACKSLASH, which results in a voice-separator. Grepping further in 
scm/* tells you that this results in a VoiceSeparator which in turn sets 
the music-property types to include "separator". After a thorough search 
in scm/*, you will finally find that this is used in the functions 
voicify-* in scm/music-functions.scm, which in turn are invoked by 
toplevel-music-functions in scorify-music ...
Anyway, the bottom line is that the actual job is done in voicify-chord 
and voicify-list in scm/music-functions.scm.
> 2. Can Hairpin inherit line-spanner-interface? If so, can this be done 
> in Scheme, or does it require C++?
It already has the line-interface and the spanner-interface as well as 3 
other interfaces. Exactly what are you missing in the Hairpin?

   /Mats