tm 4.8.3.

[elisp/tm.git] / tl-list.el

diff --git a/tl-list.el b/tl-list.el
index 8f3c781..6b0d85d 100644 (file)
--- a/tl-list.el
+++ b/tl-list.el
@@ -1,15 +1,40 @@
 ;;;
-;;; $Id: tl-list.el,v 0.3 1994/07/16 04:08:52 morioka Exp morioka $
+;;; $Id: tl-list.el,v 0.6 1994/08/28 17:10:12 morioka Exp $
 ;;;
 
 (provide 'tl-list)
 
+;;; @ list
+;;;
+
+(defun last (list)
+  "Returns the last element in the list <LIST>.
+[mol's Common Lisp emulating function]"
+  (nthcdr (- (length list) 1) list)
+  )
+
+(defun butlast (x &optional n)
+  "Returns a copy of LIST with the last N elements removed.
+[tl-list.el: imported from cl.el]"
+  (if (and n (<= n 0)) x
+    (nbutlast (copy-sequence x) n)))
+
+(defun nbutlast (x &optional n)
+  "Modifies LIST to remove the last N elements.
+[tl-list.el: imported from cl.el]"
+  (let ((m (length x)))
+    (or n (setq n 1))
+    (and (< n m)
+        (progn
+          (if (> n 0) (setcdr (nthcdr (- (1- m) n) x) nil))
+          x))))
+
+
 ;;; @ alist
 ;;;
 
 (defun put-alist (item value alist)
-  "\t(put-alist <ITEM> <VALUE> <ALIST>)\n
-If there is a pair whose car is <ITEM>, replace its cdr by <VALUE>.
+  "If there is a pair whose car is <ITEM>, replace its cdr by <VALUE>.
 If there is not such pair, create new pair (<ITEM> . <VALUE>) and
 return new alist whose car is the new pair and cdr is <ALIST>.
 [mol's ELIS emulating function]"
@@ -21,8 +46,7 @@ return new alist whose car is the new pair and cdr is <ALIST>.
     ))
 
 (defun del-alist (item alist)
-  "\t(del-alist <ITEM> <ALIST>)\n
-If there is a pair whose key is <ITEM>, delete it from <ALIST>.
+  "If there is a pair whose key is <ITEM>, delete it from <ALIST>.
 [mol's ELIS emulating function]"
   (if (equal item (car (car alist)))
       (cdr alist)