Comment #5 on issue 2729 by [email protected]: Patch: When cloning a lexer/parser, don't copy the scopes.
http://code.google.com/p/lilypond/issues/detail?id=2729
Since it speeds up #{ ... #} by a factor of 10, a candidate for cherry-picking into 2.16 before it gets released. But not without sufficient review time and exposure in 2.15.43.
