From: Han-Wen Nienhuys <hanwen@xs4all.nl>
Date: Fri, 10 Nov 2006 14:26:30 +0000 (+0100)
Subject: add count-list function
X-Git-Tag: release/2.11.0-1~47
X-Git-Url: https://git.donarmstrong.com/?a=commitdiff_plain;h=6f9f21b9d439f52b28019dba527b288b89a8a7ee;p=lilypond.git

add count-list function
---

diff --git a/scm/lily-library.scm b/scm/lily-library.scm
index 7bdf96d05d..6e30cf6ae5 100644
--- a/scm/lily-library.scm
+++ b/scm/lily-library.scm
@@ -231,6 +231,16 @@ found."
 ;; list
 
 
+(define-public (count-list lst)
+  "Given lst (E1 E2 .. ) return ((E1 . 1) (E2 . 2) ... )  "
+  (define (helper l acc count)
+    (if (pair? l)
+	(helper (cdr l) (cons (cons (car l) count) acc) (1+ count))
+	acc))
+
+
+  (reverse (helper lst '() 1)))
+  
 (define-public (list-join lst intermediate)
   "put INTERMEDIATE  between all elts of LST."