Imported Upstream version 2.18.0

[lilypond.git] / scm / skyline.scm

diff --git a/scm/skyline.scm b/scm/skyline.scm
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+;;;; This file is part of LilyPond, the GNU music typesetter.
+;;;;
+;;;; Copyright (C) 2013 Mike Solomon <mike@mikesolomon.org>
+;;;;
+;;;; LilyPond is free software: you can redistribute it and/or modify
+;;;; it under the terms of the GNU General Public License as published by
+;;;; the Free Software Foundation, either version 3 of the License, or
+;;;; (at your option) any later version.
+;;;;
+;;;; LilyPond is distributed in the hope that it will be useful,
+;;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;;;; GNU General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU General Public License
+;;;; along with LilyPond.  If not, see <http://www.gnu.org/licenses/>.
+
+(define-public (skyline-pair::empty? skyp)
+  (and (ly:skyline-empty? (ly:skyline-pair::skyline skyp UP))
+       (ly:skyline-empty? (ly:skyline-pair::skyline skyp DOWN))))
+
+;; checks if the pair is not null, and then if not empty
+(define-public (skyline-pair-and-non-empty? skyp)
+  (and (ly:skyline-pair? skyp)
+       (not (skyline-pair::empty? skyp))))