#5302 Let \tweak on event chords manipulate its elements

[David Kastrup]

Let \tweak on event chords manipulate its elements

This makes \tweak on event chords actually get heeded and creates
reasonably predictable behavior by tweaking the rhythmic elements (but
not chord-wide articulations). It also passes tweaks transparently
through music wrapper expressions (like transpositions, context
changes and other).

To achieve this, it creates and uses a get-tweakable-music function
that will deliver a list of primary music expressions tweaks should be
applied to.

This function is also used in the definition of \once to decide when a
warning for misapplication of \once might be called for.

Also contains commits:

Refactor \once

Separates the warning action of \once and its effect on overrides in
order to reduce the number of surprises.

Let \single use \tweak internally

This is less efficient than directly manipulating the @samp{tweaks}
property but closer follows the semantics of @code{\tweak},
facilitating extensions to it.

http://codereview.appspot.com/344770043

[Thomas Morley]

Hi David,

could you provide a code-example which now works, as opposed to before? From description and reading the code it's not clear to me.

[David Kastrup]

"Thomas Morley" thomas-morley@users.sourceforge.net writes:

Hi David,

could you provide a code-example which now works, as opposed to
before? From description and reading the code it's not clear to me.

{ \tweak color #red <c' g'=""> }</c'>

maybe? That's the gist of the feature. Most of the rest is just making
sure that everything continues behaving consistently.

--
David Kastrup

[Thomas Morley]

Sure about the example's syntax?
Even after applying your patch I get:

lilypond-git atest-74.ly
GNU LilyPond 2.21.0
Processing `atest-74.ly'
Parsing...
atest-74.ly:1245:29: error: syntax error, unexpected STRING
{ \tweak color #red <c' g'=" "> }
atest-74.ly:1245:29: error: string outside of text script or \lyricmode
{ \tweak color #red <c' g'=" "> }
atest-74.ly:1245:1: error: errors found, ignoring music expression</c'></c'>

{ \tweak color #red <c' g'=""> }
fatal error: failed files: "atest-74.ly"</c'>

[David Kastrup]

I checked the mail I sent and it's correct. I don't have an inkling why Sourceforge would nilly-willy add a nonsensical ="" to the example. In the mail I sent, there just was

{ \tweak color #red <c' g'> }

Try writing the same without this kind of indentation in a reply (you don't need to actually send it, just use the eye symbol for previewing it) and you'll likely get the same nonsensical ="" inserted. Sorry for the confusion.

[Thomas Morley]

Can confirm Sourceforge adds ="". Strange.

I now tried:

#(display-scheme-music 
  (extract-named-music 
    #{ \tweak color #red <c' g'> #} 
    'NoteEvent))

and (as opposed to before your patch) I got:

(list (make-music
'NoteEvent
'duration
(ly:make-duration 0)
'pitch
(ly:make-pitch 0 0))
(make-music
'NoteEvent
'duration
(ly:make-duration 0)
'pitch
(ly:make-pitch 0 4)))

Very nice.

Edit:
Code formating

[Thomas Morley]

Aargh, now I confused things while formating grrrr
The terminal output with your patch is ofcourse:

(list (make-music
        'NoteEvent
        'tweaks
        (list (list (quote color) 1.0 0.0 0.0))
        'duration
        (ly:make-duration 0)
        'pitch
        (ly:make-pitch 0 0))
      (make-music
        'NoteEvent
        'tweaks
        (list (list (quote color) 1.0 0.0 0.0))
        'duration
        (ly:make-duration 0)
        'pitch
        (ly:make-pitch 0 4)))

[Anonymous]

Passes make, make check and a full make doc

[Anonymous]

Patch on countdown for April 15th

[Anonymous]

Patch counted down - please push.

[David Kastrup]

Pushed to staging as
commit e09dc5acc4c80ba2c39f2ba3a9b7732f3e5a101d
Author: David Kastrup dak@gnu.org
Date: Sat Apr 7 22:47:53 2018 +0200

Issue 5302/3: Let \tweak on event chords manipulate its elements

This makes \tweak on event chords actually get heeded and creates
reasonably predictable behavior by tweaking the rhythmic elements (but
not chord-wide articulations).  It also passes tweaks transparently
through music wrapper expressions (like transpositions, context
changes and other).

To achieve this, it creates and uses a get-tweakable-music function
that will deliver a list of primary music expressions tweaks should be
applied to.

This function is also used in the definition of \once to decide when a
warning for misapplication of \once might be called for.

commit 2827a6353a11414b139d93c4fdbd8fce62fb067f
Author: David Kastrup dak@gnu.org
Date: Sun Apr 8 19:16:39 2018 +0200

Issue 5302/2: Refactor \once

Separates the warning action of \once and its effect on overrides in
order to reduce the number of surprises.

commit a8ecda697866c8e22b3c11a1728918929db26777
Author: David Kastrup dak@gnu.org
Date: Sat Mar 31 20:49:07 2018 +0200

Issue 5302/1: Let \single use \tweak internally

This is less efficient than directly manipulating the @samp{tweaks}
property but closer follows the semantics of @code{\tweak},
facilitating extensions to it.