From 78b62107690123d8d7a1a400e4a1d744408a05b1 Mon Sep 17 00:00:00 2001
From: "Kevin M. Rosenberg" <kevin@rosenberg.net>
Date: Fri, 10 Sep 2004 09:02:03 +0000
Subject: [PATCH] r9992: new function

---
 datetime.lisp |  2 +-
 lists.lisp    |  7 +++++++
 package.lisp  |  3 ++-
 tests.lisp    | 19 +++++++++++++++++++
 4 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/datetime.lisp b/datetime.lisp
index 52d45b2..f8aca20 100644
--- a/datetime.lisp
+++ b/datetime.lisp
@@ -89,7 +89,7 @@
     (10 . "October")
     (11 . "November")
     (12 . "December")))
-    
+
 (defun monthname (stream arg colon-p at-p &optional width (mincol 0) (colinc 1) (minpad 0) (padchar #\Space))
   "Print the name of the month (1=January) corresponding to ARG on STREAM.  This is intended for embedding in a FORMAT directive: WIDTH governs the number of characters of text printed, MINCOL, COLINC, MINPAD, PADCHAR work as for ~A"
   (let ((monthstring (cdr (assoc arg *monthnames*))))
diff --git a/lists.lisp b/lists.lisp
index 9793f27..c18fe7e 100644
--- a/lists.lisp
+++ b/lists.lisp
@@ -192,3 +192,10 @@
 	 (setf ,plist (append ,plist (list ,pkey ,value)))))))
 
 
+(defun unique-slot-values (list slot &key (test 'eql))
+  (let ((uniq '()))
+    (dolist (item list (nreverse uniq))
+      (let ((value (slot-value item slot)))
+	(unless (find value uniq :test test)
+	  (push value uniq))))))
+
diff --git a/package.lisp b/package.lisp
index 9b9316f..fe5e7a4 100644
--- a/package.lisp
+++ b/package.lisp
@@ -135,7 +135,8 @@
    #:update-plist
    #:get-plist
    #:flatten
-
+   #:unique-slot-values
+   
    ;; seq.lisp
    #:nsubseq
    
diff --git a/tests.lisp b/tests.lisp
index 86e86bd..b555555 100644
--- a/tests.lisp
+++ b/tests.lisp
@@ -379,6 +379,25 @@
     (make-url "pg" :anchor "then" :vars '(("a" . "5") ("b" . "pi")))
   "pg?a=5&b=pi#then")
 
+(defclass test-unique ()
+  ((a :initarg :a)
+   (b :initarg :b)))
+     
+
+(deftest :unique.1
+    (let ((list (list (make-instance 'test-unique :a 1 :b 1)
+		      (make-instance 'test-unique :a 2 :b 2)
+		      (make-instance 'test-unique :a 3 :b 2))))
+      (values
+       (unique-slot-values list 'a)
+       (unique-slot-values list 'b)))
+  (1 2 3) (1 2))
+
+(deftest :unique.2
+    (unique-slot-values nil 'a)
+  nil)
+     
+	   
  ;;; MOP Testing
 
 ;; Disable attrib class until understand changes in sbcl/cmucl
-- 
2.34.1