Allow tweaks in Lyrics.

Allow tweaks in Lyrics.

Since lyrics are no longer wrapped in EventChord, there is no point
in keeping tweaks from working inside of Lyrics contexts.

[Keith, 2012-05-21 06:25:13]

I'm having difficulty demonstrating that this works.

\layout { \context { \Lyrics \consists "Tweak_engraver" }}
\relative c' {c d e f }
\addlyrics { ut \tweak #'color #'red re mi fa }
?

[dak, 2012-05-21 07:49:47]

On 2012/05/21 06:25:13, Keith wrote:
> I'm having difficulty demonstrating that this works.
> 
> \layout { \context { \Lyrics \consists "Tweak_engraver" }}
> \relative c' {c d e f }
> \addlyrics { ut \tweak #'color #'red re mi fa }
> ?

This "\consists" has the same effect as this patch, making tweaks work in
lyrics, so you either need this patch, or this context def redefinition but not
both.  The symbol 'red is not a valid color, but the value of the variable red,
namely '(1.0 0.0 0.0), is.  If you write #red or #'(1.0 0.0 0.0) instead of
#'red you will be able to see an effect.

[Keith, 2012-05-21 08:00:45]

On Mon, 21 May 2012 00:49:48 -0700, <dak@gnu.org> wrote:

> #red [...] instead of #'red

Oh yes, that does it.

[janek, 2012-05-21 14:47:41]

Cool!  So for example http://lsr.dsi.unimi.it/LSR/Item?id=643 will work without
having to do something in \layout block.

I love changes like this!

[dak, 2012-05-21 15:34:14]

On 2012/05/21 14:47:41, janek wrote:
> Cool!  So for example http://lsr.dsi.unimi.it/LSR/Item?id=643 will work
without
> having to do something in \layout block.

Well, it is not exactly like the rest of the snippet is easy-peasy.

> I love changes like this!

I have the strong suspicion that the genesis of this snippet included half an
hour of head-scratching and code-rewriting because the tweak would just refuse
to work.

It is not really a spectacular change.  Just one surprise less.