Re: Issue 694 in lilypond: Enhancement: arrowed heads for microtone accidentals

[lilypond]

Comment #8 on issue 694 by joseph.wakeling: Enhancement: arrowed heads for  
microtone accidentals
http://code.google.com/p/lilypond/issues/detail?id=694

Can you clarify which points you feel are not clear?

My feeling is that it is principally a code issue, not a doc one.  Lilypond  
simply does not support effectively one of the ways of writing microtones  
-- which is to successively "shade" pitches by adding extra symbols to the  
accidentals (up/down arrows, +/-, whatever).

The _reason_ it does not support this notation for microtones is because of  
Lilypond's internal way of representing pitch -- as staff position +  
alteration.

That clashes with a notation like e.g. the arrow notation for  
quarter-tones, where the same alteration (+1/4) can be notated with two  
different accidentals: natural-with-arrow-up or sharp-with-arrow-down.

I developed a 'cheat' solution that used subtly different alterations to  
correspond to these different accidentals, but it's far from ideal.  A  
better approach would likely be to have a notation like

     \qUp c \qDown cs

... which modifies the accidental contextually.

Anyway, bottom line is, this needs code solution first and then  
documentation one.