From: pdn <pnathan@vandals.uidaho.edu>
Date: Sat, 15 Feb 2014 08:19:15 +0000 (-0800)
Subject: Add MAKE-LIST.
X-Git-Url: http://repo.macrolet.net/gitweb/?p=jscl.git;a=commitdiff_plain;h=f0a14f3e363b6d0cf1c30635f3d732b7bc0b15a4

Add MAKE-LIST.
---

diff --git a/src/list.lisp b/src/list.lisp
index 7a06dd7..368d098 100644
--- a/src/list.lisp
+++ b/src/list.lisp
@@ -197,6 +197,17 @@
     (when (eql tail object)
       (return-from tailp t))))
 
+(defun make-list (size &key (initial-element nil))
+  "Create a list of size `size` of `initial-element`s."
+  (when (< size 0)
+    (error "Size must be non-negative"))
+  (let ((newlist))
+    (do ((i 0))
+        ((= i size))
+      (push initial-element newlist)
+      (incf i))
+    newlist))
+
 (defun map1 (func list)
   (with-collect
     (while list
diff --git a/tests/list.lisp b/tests/list.lisp
index db44b9a..9580752 100644
--- a/tests/list.lisp
+++ b/tests/list.lisp
@@ -244,3 +244,7 @@
 (test (equal (let ((thing '())) (butlast thing 2)) '()))
 (test (equal (let ((thing '(1 2))) (butlast thing 2)) '()))
 (test (equal (let ((thing '())) (butlast thing 0)) '()))
+
+;; MAKE-LIST
+(test (equal (make-list 5) '(nil nil nil nil nil)))
+(test (equal (make-list 3 :initial-element 'rah) '(rah rah rah)))