Re: Accidentals from note grob

[Urs Liska]

Am 2. August 2019 08:43:51 MESZ schrieb Nils Nommensen <address@hidden>:
>That's exactly the point, I actually need the glyph name.
>If I am noch mistaken, the alteration attribute also incorporates the
>information of the key signature. I need to know which accidental is
>directly in front of the notehead.
>Therefore, the glyph name is probably what I need. However,  the line
>
>(write (ly:grob-property acc 'glyph-name))
>
>is not a string, but something else and I'm not really sure how to
>extract
>the string part of it. Do you have a suggestion?

I'm somewhat confused now. This expression "is" not a string but the result of 
the "write" procedure, which I "nothing". If you strip off the "write" part you 
have the actual glyph name (and to reiterate: the glyph name is 
"accidentals.natural", not "natural") which you can then work with.

Maybe that's not a string but a symbol (don't have a PC with me to check), in 
which case you could use the (symbol->string sym) procedure to convert it to a 
string.

Urs

>
>Am Fr., 2. Aug. 2019 um 00:16 Uhr schrieb Thomas Morley <
>address@hidden>:
>
>> Am Do., 1. Aug. 2019 um 15:23 Uhr schrieb Nils Nommensen
>> <address@hidden>:
>> >
>> > Sorry to bother you with this, but I'm really new to Lilypond and
>> Scheme. I need a String representation of the name. If I use display
>on the
>> return value, I get something like:
>"accidentals.natural"#<unspecified>".
>> > How can I extract the "natural" part?
>>
>> Well, it's not clear what you want.
>> "accidentals.natural" _is_ the glyph-name in the Emmentaler-font.
>> Ofcourse you could do some string-operation on it to get the
>> "natural", but I have my doubts this would be helpfull.
>>
>> Probably you don't want the glyph-name displayed, but rather see
>> whether there is some (which) alteration:
>>
>> \version "2.19.83"
>>
>> #(define get-accidental
>>   (lambda (note)
>>     (let*  ((acc (ly:grob-object note 'accidental-grob))
>>             (alt (ly:grob-property acc 'alteration)))
>>
>>       (newline)
>>       (write
>>         (case alt
>>           ((-1) "double-flat")
>>           ((-1/2) "flat")
>>           ((0) "natural")
>>           ((1/2) "sharp")
>>           ((1) "double-sharp")
>>           (else (format #f "not yet kown alteration: ~a" alt)))
>>       ))))
>>
>> {
>>     \override NoteHead.after-line-breaking = #get-accidental
>>     ceses'
>>     ces'
>>     c'
>>     cis'
>>     cisis'
>>
>>     ceh'
>> }
>>
>> HTH,
>>   Harm
>>