"""SNAKES is the Net Algebra Kit for Editors and Simulators

SNAKES is a Python library allowing to model all sorts of Petri nets
and to execute them. It is very general as most Petri nets annotations
can be arbitrary Python expressions while most values can be arbitrary
Python objects.

SNAKES can be further extended with plugins, several ones being
already provided, in particular two plugins implement the Petri nets
compositions defined for the Petri Box Calculus and its successors.

@author: Franck Pommereau
@organization: University of Evry/Paris-Saclay
@copyright: (C) 2005-2013 Franck Pommereau
@license: GNU Lesser General Public Licence (aka. GNU LGPL), see the
    file `doc/COPYING` in the distribution or visit [the GNU web
    site](http://www.gnu.org/licenses/licenses.html#LGPL)
@contact: franck.pommereau@ibisc.univ-evry.fr
"""

version = "0.9.16"
defaultencoding = "utf-8"

class SnakesError (Exception) :
    "An error in SNAKES"
    pass

class ConstraintError (SnakesError) :
    "Violation of a constraint"
    pass

class NodeError (SnakesError) :
    "Error related to a place or a transition"
    pass

class DomainError (SnakesError) :
    "Function applied out of its domain"
    pass

class ModeError (SnakesError) :
    "The modes of a transition cannot be found"
    pass

class PluginError (SnakesError) :
    "Error when adding a plugin"
    pass

class UnificationError (SnakesError) :
    "Error while unifying parameters"
    pass