Comment #17 on issue 2872 by [email protected]: Patch: Provide define-session and define-session-public commands
http://code.google.com/p/lilypond/issues/detail?id=2872
After staging had to be rebased, the commit has been changed to commit 9eb1eba8423cdd66f7bb0e51cb1b6104fe4e3019 Author: David Kastrup <[email protected]> Date: Mon Oct 1 14:15:17 2012 +0200 Issue 2872: Provide define-session and define-session-public commands Also moves the session logic into lily.scm instead of init.ly A session corresponds to one .ly file on the LilyPond command line; sessions are supposed to be processed independently in one LilyPond run. define-session will declare a variable that has its value recorded at the start of the first session and reinstated at the start of each following sessions. This is automatically the case for every variable defined in variables in the parser module established while loading ly/declarations-init.ly. However, not every changeable information handled in the .scm parts of LilyPond can easily or reasonably be stored in the parser module. define-session (and define-session-public) provide a way to get the same semantics for variables defined in the Scheme parts of LilyPond.
