Re: What is it with \bar "||"?

[Thomas Morley]

2014-06-29 20:52 GMT+02:00 Thomas Morley <address@hidden>:
> 2014-06-29 20:08 GMT+02:00 Patrick or Cynthia Karl <address@hidden>:
>> I recently had a problem with a \bar "||" at the end of a line suppressing 
>> the initial repeat sign in the following repeat volta section.  The answer 
>> was to use some magical \bar instead which cured the problem.  It was not 
>> clear to me then why the \bar "||" seemed to cause the following section to 
>> be treated as a new piece.
>>
>> I am now having a similar problem with the following code:
>>
>> \version "2.18.2"
>>
>> A =   \relative b' {
>>         f4 g g a        % 16
>>         \bar "||"
>>         (f4) f f f      % 17
>> }
>>
>> which throws an error: syntax error, unexpected EVENT_IDENTIFIER
>> for the attempted slur across the double bar line.
>>
>> Is there a workaround for this?  If so, should I be able to figure it out?
>
> This has nothing to do with the double barline, same would happen with
> every other barline.
>
> The Slur has to be started before \bar "whatever" is called.
>
> \relative b' {
>         f4 g g a(        % 16
>         \bar "||"
>         f4) f f f      % 17
> }
>
>> I still think the documentation about repeat signs only being suppressed at 
>> the beginning of a piece is wrong and should be fixed.  It might also be 
>> nice to have a better explanation why the \bar "||" has the effects it does.
>
>
> Again, it has nothing to do with \bar "||", see:
>
> \relative b' {
>     c1
>     \bar ""
>     \break
>     \repeat volta 2 { d }
> }
>
> The point is that \bar is a music-function setting 'whichBar and
> \repeat does as well.
>
> Now I have to guess, because lack of cc-knowledge:
> \repeat is defined in cc, \bar in scheme. I guess \repeat is called
> first and \bar second.
> I.e. two commands at the same musical moment one overriding the other.
>
> Cheers,
>   Harm

Actually it is a little more complicated.
The Repeat_acknowledge_engraver reads "defaultBarType" and takes it
into account.

Therefore the following works, although \bar "|" outputs _no_ barline
at line-begin:

\relative b' {
    c1
    c
    \bar "|"
    \break
    \repeat volta 2 { d d }
}

Setting a different defaultBarType will work, too:
\relative b' {
    \set Score.defaultBarType = #"||"
    c1
    c
    \bar "||"
    \break
    \repeat volta 2 { d d }
}

In both examples the defaultBarType is recognized and the \repeat
command is not overridden.
And prints his own repeat-sign, taken from:
startRepeatType = #".|:"
which prints a _single_ barline at line end.

To get a double barline at line-end and a repeat-barline at line-start
you can let \bar ".|:-||" override the startRepeatType:

\relative b' {
    c1
    c
    \bar ".|:-||"
    \break
    \repeat volta 2 { d d }
}

Or you can set this barline-type as the startRepeatType

\relative b' {
    c1
    c
    \once \set Score.startRepeatType = ".|:-||"
    \break
    \repeat volta 2 { d d }
}

HTH,
  Harm