;;;; PMSF-Lib --- PMSF Common Lisp Utility Library
;;;; This is copyrighted software.  See documentation for terms.
;;;; 
;;;; common-utilities.lisp --- Common utilities
;;;; 
;;;; $Id$

(cl:in-package #:pmsf-lib)

;;;; %File Description:
;;;; 
;;;; This file contains common utilities for all kinds of processing
;;;; and formatting.
;;;; 

(defun generate-printed-guid (&optional registry-format-p)
  "Generate a version 4 (PRNG) UUID and return its printed representation."
  (let ((state (make-random-state t)))
    (with-output-to-string (stream)
      (loop with chars = "0123456789abcdef"
            for index upfrom 0 below 32
            for value = (random 16 state)
            for offset = (cond
                          ((= index 12) 4)
                          ((= index 16) (+ 8 (ldb (byte 2 0) value)))
                          (t value))
            do
            (write-char (char chars offset) stream)
            (when (member index '(7 11 15 20))
              (write-char #\- stream))
            initially
            (when registry-format-p (write-char #\{ stream))
            finally
            (when registry-format-p (write-char #\} stream))))))