Re:snippet throws programming errors (Jim Long) 53

[Cynthia Karl]

> 
> Message: 7
> Date: Mon, 12 Jan 2015 20:10:20 -0800
> From: Jim Long <address@hidden>
> Subject: Re: snippet throws programming errors
> 
> On Mon, Jan 12, 2015 at 05:25:55PM -0600, Cynthia Karl wrote:
>> The following snippet:
>> 
>> \version "2.19.15"
>> 
>> music = \relative c'' { e2 g, }
>> 
>> \score       {
>>  \new Staff << \key c \major  \music >>
>>  \layout {
>>    \context { \Voice \consists "Ambitus_engraver" } 
>>  }
>> }
> 
> Your Staff line is equivalent to:
> 
> \new Staff
>  <<
>    { \key c \major }
>    { \music }
>>> 
> 
> Thus, there is no music in the first expression.  In a nutshell, that
> is what is causing your issue.

Then why does:

\version "2.19.15"

music = \relative c'' { e2 g, }

\score  {
 \new Staff << \key c \major  \music >>
 \layout {
 }
}

not cause any problem at all?  It has the same lack of music in its first 
expression.

> ...
>>      * replace "<<...>>" with {...} on the \new Staff statement.
> ...
> 
> That is the correct solution, IMO.
> 
The solution to what problem?  IMO, the problem is that my simple snippet 
causes LilyPond to declare that programing errors have occurred.  Programming 
errors are a serious problem.  Programming errors are only solved by correcting 
the program, not by avoiding them by modifying the input to the program.  You 
are suggesting that LilyPond is incapable of diagnosing a simple syntax error 
in its input.