Re: Discern post-event in music function

[David Kastrup]

Simon Albrecht <address@hidden> writes:

> Am 20.04.2017 um 17:25 schrieb address@hidden:
>> There's a `post-event?` predicate defined in
>> scm/define-music-display-methods.scm. I don't think that one's
>> easily accessible outside that module, but you can copy it:
>>
>> (define (post-event? m)
>>   (music-is-of-type? m 'post-event))
>
> Here’s the resulting function:
>
> after =
> #(define-music-function (t e m) (ly:duration? ly:music? ly:music?)
>    (let* ((post-event? (lambda (m)
>                          (music-is-of-type? m 'post-event)))
>           (post (post-event? e)))
>      #{
>        \context Bottom <<
>          #m
>          {
>            \skip $t
>            #(if post
>                 #{ <> -\tweak extra-spacing-width #empty-interval $e #}
>                 e)
>          }
>        >>
>      #}))

Well, one could just do

after =
#(define-music-function (t e m) (ly:duration? ly:music? ly:music?)
     #{
       \context Bottom <<
         #m
         {
           \skip $t
           <> $(tweak 'extra-spacing-width empty-interval e)
         }
       >>
     #})

since the $ will produce the proper kind of event (post-event or not).
Admittedly, this is cheating quite a bit.


-- 
David Kastrup