cleanup of the code belonging to slugify

src/content.lisp

@@ -20,21 +20,22 @@
   "Test if the slugs for tag A and B are equal."
   (string= (tag-slug a) (tag-slug b)))
 
-; Slugs
+;; Slugs
 
-(defun slug-char-p (char &key (allowed-chars (list #\- #\Space #\~)))
+(defun slug-char-p (char &key (allowed-chars (list #\- #\~)))
   "Determine if CHAR is a valid slug (i.e. URL) character."
   ; use the first char of the general unicode category as kind of
   ; hyper general category
-  (let ((cat (char (cl-unicode:general-category char) 0))
-		(allowed-cats (list #\L #\N)))
+  (let ((cat (aref (cl-unicode:general-category char) 0))
+		(allowed-cats (list #\L #\N))) ; allowed Unicode categories in URLs
 	(cond
-	  ((member cat allowed-cats)   't)
-	  ((member char allowed-chars) 't)
-	  (t 'nil))))
+	  ((member cat allowed-cats)   t)
+	  ((member char allowed-chars) t)
+	  (t nil))))
 
 (defun unicode-space-p (char)
-  (equal (char (cl-unicode:general-category char) 0) #\Z))
+  "Determine if CHAR is a kind of whitespace by unicode category means"
+  (char= (aref (cl-unicode:general-category char) 0) #\Z))
 
 (defun slugify (string)
   "Return a version of STRING suitable for use as a URL."