source: branches/streams/abcl/src/org/armedbear/lisp/read-sequence.lisp

;;; read-sequence.lisp
;;;
;;; Copyright (C) 2004-2005 Peter Graves
;;; $Id: read-sequence.lisp 14070 2012-08-11 12:07:52Z ehuelsmann $
;;;
;;; This program is free software; you can redistribute it and/or
;;; modify it under the terms of the GNU General Public License
;;; as published by the Free Software Foundation; either version 2
;;; of the License, or (at your option) any later version.
;;;
;;; This program is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program; if not, write to the Free Software
;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
;;;
;;; As a special exception, the copyright holders of this library give you
;;; permission to link this library with independent modules to produce an
;;; executable, regardless of the license terms of these independent
;;; modules, and to copy and distribute the resulting executable under
;;; terms of your choice, provided that you also meet, for each linked
;;; independent module, the terms and conditions of the license of that
;;; module.  An independent module is a module which is not derived from
;;; or based on this library.  If you modify this library, you may extend
;;; this exception to your version of the library, but you are not
;;; obligated to do so.  If you do not wish to do so, delete this
;;; exception statement from your version.

(in-package #:system)

(defun read-sequence (sequence stream &key (start 0) end)
  (declare (type stream stream))
  (require-type start '(integer 0))
  (if end
      (require-type end '(integer 0))
      (setf end (length sequence)))
  (let* ((element-type (expand-deftype (stream-element-type stream))))
    (cond ((eq element-type 'character)
           (do ((pos start (1+ pos)))
               ((>= pos end) pos)
             (let ((element (read-char stream nil :eof)))
               (when (eq element :eof)
                 (return pos))
               (setf (elt sequence pos) element))))
          ((equal element-type '(unsigned-byte 8))
           (if (and (vectorp sequence)
                    (equal (array-element-type sequence) '(unsigned-byte 8)))
               (read-vector-unsigned-byte-8 sequence stream start end)
               (do ((pos start (1+ pos)))
                   ((>= pos end) pos)
                 (let ((element (read-8-bits stream nil :eof)))
                   (when (eq element :eof)
                     (return pos))
                   (setf (elt sequence pos) element)))))
          (t
           (do ((pos start (1+ pos)))
               ((>= pos end) pos)
             (let ((element (read-byte stream nil :eof)))
               (when (eq element :eof)
                 (return pos))
               (setf (elt sequence pos) element)))))))