X-Git-Url: https://git.hcoop.net/bpt/guile.git/blobdiff_plain/e5d2c2fa4fb0586308f4d716c9ae9d3ce47ae237..8a7fb63c90b94738d9797080409dcb078fa3e8f7:/ice-9/common-list.scm

diff --git a/ice-9/common-list.scm b/ice-9/common-list.scm
index 02d1858e2..c5c8c0609 100644
--- a/ice-9/common-list.scm
+++ b/ice-9/common-list.scm
@@ -124,6 +124,14 @@ Analogous to some but returns #t as soon as an application of PRED returns #f,
 or #f otherwise."
   (not (apply every pred ls)))
 
+(define-public (count-if pred l)
+  "Returns the number of elements in L such that (PRED element)
+returns true."
+  (let loop ((n 0) (l l))
+    (cond ((null? l) n)
+	  ((pred (car l)) (loop (+ n 1) (cdr l)))
+	  (else (loop n (cdr l))))))
+
 (define-public (find-if pred l)
   "Searches for the first element in L such that (PRED element)
 returns true. If it finds any such element in L, element is
@@ -225,10 +233,11 @@ non-#f return values of P."
 
 (define-public (uniq l)
   "Return a list containing elements of L, with duplicates removed."
-  (if (null? l)
-      '()
-      (let ((u (uniq (cdr l))))
-	(if (memq (car l) u)
-	    u
-	    (cons (car l) u)))))
-
+  (let loop ((acc '())
+	     (l l))
+    (if (null? l)
+	(reverse! acc)
+	(loop (if (memq (car l) acc)
+		  acc
+		  (cons (car l) acc))
+	      (cdr l)))))