[PRL] Looking for 2 bits of emacs code

[David Herman]

Don't know if there's a built-in escape function for the browse-url 
package but here's an approximation:

;; ---
;; http://www.zvon.org/tmRFC/RFC2396/Output/chapter2.html

(defconst lower      (append "abcdefghijklmnopqrstuvwxyz" nil))
(defconst upper      (append "ABCDEFGHIJKLMNOPQRSTUVWXYZ" nil))
(defconst alpha      (append lower upper nil))
(defconst num        (append "0123456789" nil))
(defconst alphanum   (append alpha num nil))
(defconst mark       (append "-_.!~*'()" nil))
(defconst unreserved (append alphanum mark nil))

;; google-url : string -> string
(defun google-url (str)
   (concat "http://www.google.com/search?hl=en&ie=UTF-8&oe=UTF-8&q="
           (escape str)
           "&btnG=Google+Searchstr"))

;; escape : string -> string
(defun escape (str)
   (escape-helper (append str nil) ""))

;; escape-helper : (listof char) string -> string
(defun escape-helper (aloc result)
   (if (null aloc)
       result
       (escape-helper (cdr aloc) (concat result (escape-char (car 
aloc))))))

;; escapep : char -> boolean
(defun escapep (c)
   (not (memq c unreserved)))

;; escape-char : char -> char
(defun escape-char (c)
   (cond
     ((eq c ?\ ) "+")
     ((escapep c) (format "%%%x" c))
     (t (string c))))
;; ---

Dave