Re: Trouble with concat in a markup command

[Alec Bartsch]

A-ha! That makes sense and works great, thanks David.

On Sat, May 4, 2024 at 1:54 AM David Kastrup <dak@gnu.org> wrote:

Alec Bartsch <alec.bartsch@gmail.com> writes:

> I'm attempting to write a markup command that, in addition to other
> formatting, strips a trailing # or b character off the end of the text
> argument and replaces it with the appropriate accidental markup. I think
> I'm super-close but stuck on the proper syntax for passing a markup list to
> the concat. Here's what I've got so far:
>
> #(define-markup-command (page-header layout props text) (markup?)
>     "Page header style including optional trailing accidental"
>     (let* (
>         (last-char (string-ref text (1- (string-length text))))
>         (prefix (substring text 0 (1- (string-length text))))
>         )
>         (interpret-markup layout props
>             (markup #:override '(font-name . "Avenir Heavy") #:fontsize 5
>                 (make-concat-markup (cond
>                     ((char=? last-char #\#) (list prefix #:hspace 0.2
> #:fontsize -2.5 #:raise 0.6 #:sharp))
>                     ((char=? last-char #\b) (list prefix #:hspace 0.2
> #:fontsize -2.5 #:raise 0.6 #:flat))
>                     (else (list text))
>                 ))
>             )
>         )
>     )
> )
>
> \markup \page-header "Key of Bb"

The markup macro is something that works so-soish.  As a macro, it
doesn't wait for its arguments to be evaluated but looks at them before
they are being evaluated.  It (hopefully) won't look inside a function
call like make-concat-markup.  #{ \markup ... #} tends to behave more
predictable if slower.  Fixing this up for your use case you'd write
something akin to



--
David Kastrup