Re: Question about 'back quote' in scheme markups within Documentation examples

[Carl Sorensen]

On 6/9/10 7:34 AM, "James Lowe" <address@hidden> wrote:

> Hello,
> 
> Going on from the 'curly quotes' problem that was resolved a couple of
> days back in our documentation, I noticed in the NR while scanning
> through another 'odd' single quote mark after the hash (#) character.
> 
> \override #`(direction . ,UP)

This has UP evaluated at the time the cons cell is made.
> 
> instead of
> 
> \override #'(direction . ,UP)

This is incorrect.  The alternative syntax would be

\override #'(direction . UP)

which would put the symbol UP in the cons cell.


> 
> See attached screenshot for an example
> 
> An example is from the the NR Appendix, 'A.8.2 Align'
> 
> http://lilypond.org/doc/v2.13///Documentation/notation/align
> 
> specifically '\dir-column args (markup list)'
> 
> I wondered if anyone can tell me if this is a mistake or what the
> significance of the back-quote is vs the standard singe quote?

The back-quote means that any expression in the back-quoted list that is
preceded by a comma will be evaluated.  The regular single quote means that
nothing in the list will be evaluated; the list will just be assembled.

HTH,

Carl