New function: integer-to-string

diff --git a/lispstrack.lisp b/lispstrack.lisp
index b637d10..6325f58 100644 (file)
--- a/lispstrack.lisp
+++ b/lispstrack.lisp
@@ -23,6 +23,15 @@
              separator
              (join (cdr list) separator)))))
 
+(defun integer-to-string (x)
+  (let ((digits nil))
+    (while (not (= x 0))
+      (push (mod x 10) digits)
+      (setq x (truncate x 10)))
+    (join (mapcar (lambda (d) (string (char "0123456789" d)))
+             digits)
+          "")))
+
 ;;;; Reader
 
 ;;; It is a basic Lisp reader. It does not use advanced stuff