Re: unpacking a list

[Urs Liska]

Am 30.11.2015 um 10:03 schrieb David Kastrup:
> Urs Liska <address@hidden> writes:
>
>> Am 30.11.2015 um 09:27 schrieb Urs Liska:
>>
>> Maybe, not for having someone else do the work for me but as an
>> incentive to learn:
>>
>> I assume I could also rewrite the following code in a similar fashion?
>>
>> % Produce the code for coloring one grob in a (make-music) expression
>> #(define (color-element grob color)
>>    (make-music
>>     'ContextSpeccedMusic
>>     'context-type
>>     'Bottom
>>     'element
>>     (make-music
>>      'OverrideProperty
>>      'once
>>      #t
>>      'pop-first
>>      #t
>>      'grob-value
>>      color
>>      'grob-property-path
>>      (list (quote color))
>>      'symbol
>>      grob)))
>>
>> What would that be in the newer, LilyPond-ish syntax?
> Oh, #{ ... #} is not new.  It's been there since basically forever at
> least for straightforward music expressions (rather than layout
> definitions, markups, and other stuff).  It became more versatile around
> 2.14 and started to work nicely with lexical closures at a similar point
> of time.
>
> The above would roughly be
>
> #(define (color-element grob color)
>   #{ \once \override #grob . color = #color #})
>
> Note that the default context for overrides is Bottom anyway, so you
> don't need to write \override Bottom . #grob . color here.
>

Oh, seems like a typical case of not seeing the forest for the trees ...

Thanks for the explanations
Urs