From: David Kastrup <dak@gnu.org>
Date: Sun, 30 Oct 2011 06:54:39 +0000 (+0100)
Subject: Implement fraction? predicate checking for pair of unsigned integers
X-Git-Tag: release/2.15.17-1~11
X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;h=52746445ea483c3c7ea7d12eb96584b2baa7a40d;p=lilypond.git

Implement fraction? predicate checking for pair of unsigned integers
---

diff --git a/scm/c++.scm b/scm/c++.scm
index 915e7e6283..5a5f8e0bad 100644
--- a/scm/c++.scm
+++ b/scm/c++.scm
@@ -25,6 +25,11 @@
   (and (pair? x)
        (number? (car x)) (number? (cdr x))))
 
+(define-public (fraction? x)
+  (and (pair? x)
+       (integer? (car x)) (integer? (cdr x))
+       (>= (car x) 0) (>= (cdr x) 0)))
+
 (define-public (number-or-grob? x)
   (or (ly:grob? x) (number? x)))
 
diff --git a/scm/lily.scm b/scm/lily.scm
index 3ad7fb580e..4ab0164850 100644
--- a/scm/lily.scm
+++ b/scm/lily.scm
@@ -508,6 +508,7 @@ LilyPond safe mode.  The syntax is the same as `define*-public'."
   `((,boolean-or-symbol? . "boolean or symbol")
     (,color? . "color")
     (,cheap-list? . "list")
+    (,fraction? . "fraction, as pair")
     (,grob-list? . "list of grobs")
     ;; this is built on cheap-list
     (,list-or-symbol? . "list or symbol")