Re: Patch: Make #{ ... #} wagonloads more useful

[David Kastrup]

David Kastrup <address@hidden> writes:

> Previously #{ ... #} created only sequential music.  This changes it to
> accept everything an assignment accepts.  Incompatibility to before:
> #{ #} returns a void music expression, #{ music #} does not create a
> sequential music list but just a single music event,
> only #{ music music ... #} works just the same as before.
>
> <URL:http://codereview.appspot.com/4974046>

Here is a fun example:

the extending documentation contains the example

    Inline Scheme code

    The main disadvantage of `\tweak' is its syntactical inflexibility.
    For example, the following produces a syntax error.

    F = \tweak #'font-size #-3 -\flageolet

    \relative c'' {
      c4^\F c4_\F
    }

It then procedes to work around using

    F = #(let ((m (make-music 'ArticulationEvent
                              'articulation-type "flageolet")))
           (set! (ly:music-property m 'tweaks)
                 (acons 'font-size -3
                        (ly:music-property m 'tweaks)))
           m)

Ugh.  But with the new patch, this can be reduced to

    F = ##{-\tweak #'font-size #-3 -\flageolet#}

If you check the resulting expressions, you'll find that apart from the
added origin property they are identical.

Is that smooth or what?

-- 
David Kastrup