lispdoc - results for alphanumericp

(alphanumericp char)

Function: Given a character-object argument, ALPHANUMERICP returns T if the argument is either numeric or alphabetic.

Example:

(defun url-reserved-character-p (c)
  (not
   (or
    (member c
            '(#\- #\_ #\. #\! #\~ #\* #\' #\(
              #\)))
    (alphanumericp c))))

Mentioned in:
CLtL2 - 13. Characters
CLtL2 - 13.2. Predicates on Characters
HyperSpec - Function ALPHANUMERICP