Re: Let's make TextSpanners easier to use!

[Neil Puttock]

2008/10/29 Valentin Villenave <address@hidden>:
> 2008/10/29 Neil Puttock <address@hidden>:

>> As a minor refinement, you could use assoc-get instead of assoc.
>
> ??
> address@hidden ~]$ guile
> guile> (help assoc-get)
> Did not find any object named `assoc-get'
> guile>

It's in lily-library.scm. :)

>> Hmm, this isn't as elegant as make-text-span itself; you can't use markup.
>
> Do you know how I could (other than using (ly:markup?))?

Not that would be approved for inclusion in the source.

> OK. I have to confess I haven't understood yet how the backquote
> works. IIUC, it 'quotes all the keys in the alist, and then I have to
> ,unquote the ones i want to actually use as variables?

Don't worry, I'm not sure I understand either. :)

What I do know is that backquote is used to create a list template
(mainly for use in macros); any element in the template which isn't
,unquoted appears verbatim in the resulting list, whereas an ,unquoted
element is evaluated.  So in the txt example, without unquote the
resulting list contains the symbol 'txt; unquoted, it contains the
internal value of txt, i.e., the string.

> Would you, by any chance, have an idea about how to make it possible to have
>
> c1\startSpan "spanner attached to note" c1\endSpan
>
> without using a music function?
>
> (If you do have an idea, this would also be useful for Graham's
> compound dynamics.)

I've puzzled over this, but can't think of anything which might work.

Regards,
Neil