# Copyright (c) 2008-2009 Pedro Matiello <pmatiello@gmail.com>
#                         Salim Fadhley <sal@stodge.org>
#
# Permission is hereby granted, free of charge, to any person
# obtaining a copy of this software and associated documentation
# files (the "Software"), to deal in the Software without
# restriction, including without limitation the rights to use,
# copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the
# Software is furnished to do so, subject to the following
# conditions:

# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.

# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
# OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
# HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
# WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
# FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
# OTHER DEALINGS IN THE SOFTWARE.


"""
Exceptions.
"""


class python_graph_exception(RuntimeError):
    """
    A base-class for the various kinds of errors that occur in the the python-graph class.
    """

class unreachable(python_graph_exception):
    """
    Goal could not be reached from start.
    """
    def __init__( self, start, goal ):
        msg = "Node %s could not be reached from node %s" % ( repr(goal), repr(start) )
        python_graph_exception.__init__(self, msg)
        self.start = start
        self.goal = goal
