X-Git-Url: http://repo.macrolet.net/gitweb/?a=blobdiff_plain;f=src%2Fsequence.lisp;h=be36e994fedeef7904f48a9c61b48c6b91dcb71f;hb=18ada11fb234e336a3d2ac4370d384d80d36f9f0;hp=cda0b411dfb489547718835272fc9d2ea54cb898;hpb=e2040ea9a5d5794b68a34277d459d52b475d6eff;p=jscl.git

diff --git a/src/sequence.lisp b/src/sequence.lisp
index cda0b41..be36e99 100644
--- a/src/sequence.lisp
+++ b/src/sequence.lisp
@@ -13,6 +13,8 @@
 ;; You should have received a copy of the GNU General Public License
 ;; along with JSCL.  If not, see <http://www.gnu.org/licenses/>.
 
+(/debug "loading sequence.lisp!")
+
 (defun not-seq-error (thing)
   (error "`~S' is not of type SEQUENCE" thing))
 
@@ -179,3 +181,29 @@
 
 (defun copy-seq (sequence)
   (subseq sequence 0))
+
+
+;;; Reduce (based on SBCL's version)
+
+(defun reduce (function sequence &key key from-end (start 0) end (initial-value nil ivp))
+  (let ((key (or key #'identity))
+        (end (or end (length sequence))))
+    (if (= end start)
+        (if ivp initial-value (funcall function))
+        (macrolet ((reduce-list (function sequence key start end initial-value ivp from-end)
+                     `(let ((sequence
+                             ,(if from-end
+                                  `(reverse (nthcdr ,start ,sequence))
+                                  `(nthcdr ,start ,sequence))))
+                        (do ((count (if ,ivp ,start (1+ ,start))
+                                    (1+ count))
+                             (sequence (if ,ivp sequence (cdr sequence))
+                                       (cdr sequence))
+                             (value (if ,ivp ,initial-value (funcall ,key (car sequence)))
+                                    ,(if from-end
+                                         `(funcall ,function (funcall ,key (car sequence)) value)
+                                         `(funcall ,function value (funcall ,key (car sequence))))))
+                            ((>= count ,end) value)))))
+          (if from-end
+              (reduce-list function sequence key start end initial-value ivp t)
+              (reduce-list function sequence key start end initial-value ivp nil))))))