On 29/07/16 21:32, catalaco - wrote:
The last paragraph of 1.2.2 LilyPond variableshttp://lilypond.org/doc/v2.18/Documentation/extending/lilypond-variables in Extending LilyPondhttp://lilypond.org/doc/v2.18/Documentation/extending/index is very hard to understand.
The whole thing might need to be rewritten but I don't understand enough to do that. All I can do is offer suggestions for rephrasing, although I might be misinterpreting as I'm not fully understanding what I'm reading!Original text
The usual way to refer to Lilypond variables, LilyPond Scheme syntaxhttp://lilypond.org/doc/v2.18/Documentation/extending/lilypond-scheme-syntax, is to call them using a backslash, i.e., \twentyFour.
Since this creates a copy of the value for most of LilyPond’s internal types, in particular music expressions, music functions don’t usually create copies of material they change. For this reason, music expressions given with # should usually not contain material that is not either created from scratch or explicitly copied rather than directly referenced.
Rephrased
Lilypond variables are usually called using a backslash, e.g. \twentyFour (see LilyPond Scheme syntaxhttp://lilypond.org/doc/v2.18/Documentation/extending/lilypond-scheme-syntax), which creates a copy of the value. For that reason music functions in LilyPond don't usually create copies of material they change. Because of this, scheme music expressions written with the # syntax should not directly reference material. They should only be used for material created from scratch or explicitly copied.
Greetings,
Martin
Doc: Extending - rewrite - LilyPond Variables
Issue 4948
Last para of Extending/LP variables
rewrite for clarity.
http://codereview.appspot.com/309820043
Diff:
With David K's suggestions.
http://codereview.appspot.com/309820043
Passes make, make check and a full make doc.
Patch on countdown for August 9th.
Patch counted down - please push.
author James Lowe pkx166h@gmail.com
Sun, 31 Jul 2016 17:32:44 +0100 (17:32 +0100)
committer James Lowe pkx166h@gmail.com
Wed, 10 Aug 2016 17:23:08 +0100 (17:23 +0100)
commit 3025442087de8dd3f88736290887ced86e360c25