Re: within \markup, how to \translate by width of another markup?

[Werner LEMBERG]

>> AFAICS, we are back to square one, needing the possibility to
>> `\translate` something by the width of another markup.  I will cook
>> something up and see how well it works.
>
>
> Probably
>
> ```
> \version "2.22.2"
>
> #(define-markup-command (translate-by-extent-of layout props axis direction 
> extent-source mkup)
>    (index? ly:dir? markup? markup?)
>    (let* ((stil (interpret-markup layout props mkup))
>           (source-stil (interpret-markup layout props extent-source))
>           (ext (ly:stencil-extent source-stil axis))
>           (trans (* direction (interval-length ext))))
>    (ly:stencil-translate-axis stil trans axis)))
>
>
> \markup \box \number \column {
>   \translate-by-extent-of #X #RIGHT 9 \right-align { 11 10 }
>   6 5 4 3 2 1
> }
> ```
>
>
> That being said, I think I would rather define an interface to
> align a markup on another markup.
>
> ```
> \version "2.22.2"
>
> #(define-markup-command (align-on-other layout props axis self-align-dir 
> other-align-dir
>                                         alignment-markup printed-markup)
>    (index? number? number? markup? markup?)
>    (let* ((stil (interpret-markup layout props printed-markup))
>           (stil-ext (ly:stencil-extent stil axis))
>           (align-stil (interpret-markup layout props alignment-markup))
>           (align-ext (ly:stencil-extent align-stil axis))
>           (trans (- (interval-index align-ext other-align-dir)
>                     (interval-index stil-ext self-align-dir))))
>      (ly:stencil-translate-axis stil trans axis)))
>
> \markup \number \column {
>   \align-on-other #X #RIGHT #RIGHT 9 { 11 10 }
>   6 5 4 3 2 1
> }
> ```

Excellent, thanks!  I like `\align-on-other` very much.

> By the way, are you sur this is the canonical presentation for
> figured bass digits? \figures { <11 10 6 5 4 3 2 1> } seems to do a
> kind of \center-column (using the ad-hoc translation you mentioned),
> which what I would expect ...

I'm still investigating.  Whatever the outcome is, `\align-on-other`
serves all useful possibilities very well and is definitely better
than the current ad-hoc translation.


    Werner