MAPLIST.

diff --git a/src/list.lisp b/src/list.lisp
index dabd201..ad0e7a6 100644 (file)
--- a/src/list.lisp
+++ b/src/list.lisp
@@ -194,6 +194,24 @@
                (rplaca tail (cdar tail)))
              (collect (apply func elems))))))))
 
+(defun mapn (func list)
+  (with-collect
+    (while list
+      (collect (funcall func list))
+      (setq list (cdr list)))))
+
+(defun maplist (func list &rest lists)
+  (let ((lists (cons list lists)))
+    (with-collect
+      (block loop
+        (loop
+           (let ((elems (mapn #'car lists)))
+             (do ((tail lists (cdr tail)))
+                 ((null tail))
+               (when (null (car tail)) (return-from loop))
+               (rplaca tail (cdar tail)))
+             (collect (apply func elems))))))))
+
 (defun mapc (func &rest lists)
   (do* ((elems (map1 #'car lists) (map1 #'car lists-rest))
         (lists-rest (map1 #'cdr lists) (map1 #'cdr lists-rest)))

diff --git a/tests/list.lisp b/tests/list.lisp
index 4a99d8c..ffc672d 100644 (file)
--- a/tests/list.lisp
+++ b/tests/list.lisp
@@ -204,6 +204,14 @@
 ;; MAPCAR
 (test (equal (mapcar #'+ '(1 2) '(3) '(4 5 6)) '(8)))
 
+;; MAPLIST
+(test (equal '((1 2 3 4 1 2 1 2 3) (2 3 4 2 2 3))
+            (maplist #'append '(1 2 3 4) '(1 2) '(1 2 3))))
+(test (equal '((FOO A B C D) (FOO B C D) (FOO C D) (FOO D))
+            (maplist #'(lambda (x) (cons 'foo x)) '(a b c d))))
+(test (equal '(0 0 1 0 1 1 1)
+            (maplist #'(lambda (x) (if (member (car x) (cdr x)) 0 1)) '(a b a c d b c))))
+
 ;; MAPC
 (test (equal (mapc #'+ '(1 2) '(3) '(4 5 6)) '(1 2)))
 (test (let (foo)