From: Chris Hanson <org/chris-hanson/cph>
Date: Thu, 28 Apr 2005 04:33:50 +0000 (+0000)
Subject: Implement COUNT-MATCHING-ITEMS and COUNT-NON-MATCHING-ITEMS.
X-Git-Tag: 20090517-FFI~1319
X-Git-Url: https://birchwood-abbey.net/git?a=commitdiff_plain;h=4c31ad928eab4b6c637f71ec9f9a41cbeed11183;p=mit-scheme.git

Implement COUNT-MATCHING-ITEMS and COUNT-NON-MATCHING-ITEMS.
---

diff --git a/v7/src/runtime/list.scm b/v7/src/runtime/list.scm
index 44db97bf1..7867e17d9 100644
--- a/v7/src/runtime/list.scm
+++ b/v7/src/runtime/list.scm
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: list.scm,v 14.48 2005/03/29 05:02:11 cph Exp $
+$Id: list.scm,v 14.49 2005/04/28 04:33:36 cph Exp $
 
 Copyright 1986,1987,1988,1989,1990,1991 Massachusetts Institute of Technology
 Copyright 1992,1993,1994,1995,1996,2000 Massachusetts Institute of Technology
@@ -691,6 +691,22 @@ USA.
 	      (error:not-list items 'FIND-MATCHING-ITEM))
 	  #f))))
 
+(define (count-matching-items items predicate)
+  (do ((items* items (cdr items*))
+       (n 0 (if (predicate (car items*)) (+ n 1) n)))
+      ((not (pair? items*))
+       (if (not (null? items*))
+	   (error:not-list items 'COUNT-MATCHING-ITEMS))
+       n)))
+
+(define (count-non-matching-items items predicate)
+  (do ((items* items (cdr items*))
+       (n 0 (if (predicate (car items*)) n (+ n 1))))
+      ((not (pair? items*))
+       (if (not (null? items*))
+	   (error:not-list items 'COUNT-NON-MATCHING-ITEMS))
+       n)))
+
 (define (keep-matching-items items predicate)
   (let ((lose (lambda () (error:not-list items 'KEEP-MATCHING-ITEMS))))
     (cond ((pair? items)
diff --git a/v7/src/runtime/runtime.pkg b/v7/src/runtime/runtime.pkg
index 9a0404835..d81829855 100644
--- a/v7/src/runtime/runtime.pkg
+++ b/v7/src/runtime/runtime.pkg
@@ -1,6 +1,6 @@
 #| -*-Scheme-*-
 
-$Id: runtime.pkg,v 14.540 2005/04/16 04:05:27 cph Exp $
+$Id: runtime.pkg,v 14.541 2005/04/28 04:33:50 cph Exp $
 
 Copyright 1988,1989,1990,1991,1992,1993 Massachusetts Institute of Technology
 Copyright 1994,1995,1996,1997,1998,1999 Massachusetts Institute of Technology
@@ -2122,6 +2122,8 @@ USA.
 	  circular-list
 	  cons
 	  cons*
+	  count-matching-items
+	  count-non-matching-items
 	  del-assoc
 	  del-assoc!
 	  del-assq