00001 # Software License Agreement (BSD License) 00002 # 00003 # Copyright (c) 2013, Open Source Robotics Foundation Inc. 00004 # All rights reserved. 00005 # 00006 # Redistribution and use in source and binary forms, with or without 00007 # modification, are permitted provided that the following conditions 00008 # are met: 00009 # 00010 # * Redistributions of source code must retain the above copyright 00011 # notice, this list of conditions and the following disclaimer. 00012 # * Redistributions in binary form must reproduce the above 00013 # copyright notice, this list of conditions and the following 00014 # disclaimer in the documentation and/or other materials provided 00015 # with the distribution. 00016 # * Neither the name of Willow Garage, Inc. nor the names of its 00017 # contributors may be used to endorse or promote products derived 00018 # from this software without specific prior written permission. 00019 # 00020 # THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 00021 # "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 00022 # LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 00023 # FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE 00024 # COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, 00025 # INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, 00026 # BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 00027 # LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER 00028 # CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 00029 # LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN 00030 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 00031 # POSSIBILITY OF SUCH DAMAGE. 00032 00033 00034 class MessageList(object): 00035 00036 def __init__(self): 00037 super(MessageList, self).__init__() 00038 self._messages = [] 00039 00040 def __getitem__(self, key): 00041 return self._messages[len(self._messages) - key - 1] 00042 00043 def __delitem__(self, key): 00044 if isinstance(key, slice): 00045 assert key.step is None or key.step == 1, 'MessageList.__delitem__ not implemented for slices with step argument different than 1' 00046 del self._messages[len(self._messages) - key.stop:len(self._messages) - key.start] 00047 else: 00048 del self._messages[len(self._messages) - key - 1] 00049 00050 def __iter__(self): 00051 return reversed(self._messages) 00052 00053 def __reversed__(self): 00054 return iter(self._messages) 00055 00056 def __contains__(self, item): 00057 return item in self._messages 00058 00059 def __len__(self): 00060 return len(self._messages) 00061 00062 def extend(self, item): 00063 self._messages.extend(item)