Re: Nashville notation as chord symbols

[David Kastrup]

Thomas Morley <address@hidden> writes:

> 2015-06-19 6:48 GMT+02:00 David Kastrup <address@hidden>:
>> Thomas Morley <address@hidden> writes:
>>
>>> 2015-06-18 23:37 GMT+02:00 David Kastrup <address@hidden>:
>>>> Thomas Morley <address@hidden> writes:
>>>>>
>>>>> \version "2.18.2"
>>>>>
>>>>> #(define nashville-chord-engraver
>>>>>    (let ((root (ly:make-pitch 0 0 0)))
>>>>
>>>> That should rather be
>>>>
>>>> #(define (nashville-chord-engraver context)
>>>>    (let ((root (ly:make-pitch 0 0 0)))
>>>> [...]
>>>>
>>>
>>> Thanks.
>>>
>>> Not sure what exactly you mean with the following.
>>> Is it an additional comment to the above or a second concern?
>>>
>>>> In your proposal, all engraver instances share the same "root", a recipe
>>>> for trouble.
>>
>> It is an additional comment on the above.  If you have one transposed
>> voice, for example, having all engravers working with the same "root" is
>> not going to be a good idea.  Or when having a \markup { \score ... }
>> inside for some purpose, there will still only be one root for both the
>> enclosing score and the score inside the markup.
>
> if I understand your hints correctly, then some use-cases will break
> or at least return wrong/weird output.
> Though, I wasn't able to find any.
> May I ask you, if you've the time to find and supply an example,
> triggering the problem?
>
> Here, what I've tried so far (the mainly unchanged engraver is included):
>
> \version "2.18.2"
>
> #(define (nashville-chord-engraver context)

Stop.  I was describing the problems with the _original_ version that
was using

#(define nashville-chord-engraver ...

instead.

After changing this static definition into a function, the problem is of
course fixed: every function call gets its own "root" variable.

That was my point.

So if you want to see the described problem, you need to change the
nashville-chord-engraver definition back to the original version.

-- 
David Kastrup