Re: get an accidental to not print

[Jonathan Henkelman]

Trevor Bača <trevorbaca <at> gmail.com> writes:

> > For the record. I understand both of Trevors examples, but looking through 
the
> > programmers ref to try and understand Mats' fix...  'stencil' is listed of
> > type "unknown" and the doc says it represents the "symbol to print". How 
does
> > passing it false result in a symbol not being printed?  Should the doc be
> > updated to say something like: "The symbol to print, or don't print if 
false"?

>   \override Whatever #'outside-staff-priority = ##f
> 
> ... then you're basically saying to the optimized vertical spacing
> algorithm "hey, just don't even consider the Whatever grob when you do
> the vertical stuff."
...
> Not sure where the convention about numeric (and other) parameters
> taking ##f appears in the docs, but it's a good convention to know.

Thanks much Trevor.  That _is_ a useful convention to know.

I just searched the PDF manual 2.10.0 for all occurances of ##f and false and 
didn't get any reference to this.  Could I propose adding the following 
sentance to the end of the last paragraph in Section 9.3.1 "Constructing a 
tweak".  Feel free to modify it as much as necessary as I am still a relative 
newbie to LP.

*** Start Insertion ***

For many properties, regardless of the data type of the property, setting the 
property to false (##f) will result in turning it off, causing Lilypond to 
ignore that property entirely.  This is particularly useful for turning off 
grob properties which may otherwise be causing problems.

*** End Insertion *** 

Thanks much,
Jonathan