Re: New Issue: Disallow uncontained context-spec-music on top level

[David Kastrup]

Simon Albrecht <address@hidden> writes:

> <https://sourceforge.net/p/testlilyissues/issues/4617/>
>
> If
>
> $ git grep'= #(context-spec-music'
> Documentation/snippets/additional-voices-to-avoid-collisions.ly:voiceFive=  
> #(co
> ly/declarations-init.ly:melisma=  #(context-spec-music (make-property-set 
> 'melis
> ly/declarations-init.ly:melismaEnd=  #(context-spec-music 
> (make-property-unset '
> ly/property-init.ly:voiceOne=  #(context-spec-music (make-voice-props-set 0)
> ly/property-init.ly:voiceTwo=  #(context-spec-music (make-voice-props-set 1)
> ly/property-init.ly:voiceThree=  #(context-spec-music (make-voice-props-set 2)
> ly/property-init.ly:voiceFour=  #(context-spec-music (make-voice-props-set 3)
> ly/property-init.ly:oneVoice=  #(context-spec-music (make-voice-props-revert)
>  
>
> doesn’t deceive me, there are seven commands which output
> context-spec-music.
>
> It’s currently possible to use these on top level:
>
> %%%%% \version  "2.19.27"
> \melisma
> %%%%%

It's possible to use any music variable at top level.

> gives no warning or other message, but the attached (nonsense) output.
>
> This becomes a problem when ")" has been redefined and somewhere else
> a Scheme expression has mismatched braces:
>
> %%%%% \version  "2.19.27"
> ")" =\melismaEnd
> #(define test "foo"))
> %%%%%
>
> An extremely annoying case to debug, I can tell you.
>
> So redefining ")" should not preclude the warnings which turn up
> without the redefinition.

What warnings?  You are talking about an error here:

/tmp/riga.ly:1:1: error: syntax error, unexpected EVENT_IDENTIFIER

and that error is based exclusively on the _content_ of ")" and not
related to any independently produced warnings.  For example, you can
write \] and just get
/tmp/riga.ly:1:1: warning: cannot find start of ligature

Making an error based on context-spec-music would be quite strange, by
the way, since _many_ toplevel expressions are context-spec-music, like
\new PianoStaff ...

-- 
David Kastrup