Simple raw string reader macro

raw-reader.lisp

;; Beware: #" is actually not reserved for the user. See:
;; http://www.lispworks.com/documentation/HyperSpec/Body/02_dh.htm

(defun read-raw-string (stream subchar arg)
  (declare (ignore subchar arg))
  (with-output-to-string (out)
    (loop for char = (read-char stream nil nil)
          while (and char (char/= char #\"))
          do (write-char char out))))

(set-dispatch-macro-character #\# #\" #'read-raw-string)

;; CL-USER> #"\<foo\>"
;; "\\<foo\\>"