September 2017 Update

Task/URL-encoding/Common-Lisp/url-encoding.lisp

@@ -0,0 +1,15 @@
+(defun needs-encoding-p (char)
+  (not (digit-char-p char 36)))
+
+(defun encode-char (char)
+  (format nil "%~2,'0X" (char-code char)))
+
+(defun url-encode (url)
+  (apply #'concatenate 'string
+         (map 'list (lambda (char)
+                      (if (needs-encoding-p char)
+                          (encode-char char)
+                          (string char)))
+              url)))
+
+(url-encode "http://foo bar/")