#------------------------------------------------------------------------------
# Copyright (c) 2013-2017, Nucleic Development Team.
#
# Distributed under the terms of the Modified BSD License.
#
# The full license is in the file COPYING.txt, distributed with this software.
#------------------------------------------------------------------------------
from .catom import Member, DefaultValue, Validate
class Enum(Member):
""" A member where the value can be one in a sequence of items.
"""
__slots__ = ()
def __init__(self, *items):
""" Initialize an Enum.
Parameters
----------
*items
The allowed values which can be assigned to the enum.
"""
if len(items) == 0:
raise ValueError('an Enum requires at least 1 item')
self.set_default_value_mode(DefaultValue.Static, items[0])
self.set_validate_mode(Validate.Enum, items)
@property
def items(self):
""" A readonly property which returns the items in the enum.
"""
return self.validate_mode[1]
def added(self, *items):
""" Create a clone of the Enum with added items.
Parameters
----------
*items
Additional items to include in the Enum.
Returns
-------
result : Enum
A new enum object which contains all of the original items
plus the new items.
"""
olditems = self.items
newitems = olditems + items
clone = self.clone()
clone.set_validate_mode(Validate.Enum, newitems)
return clone
def removed(self, *items):
""" Create a clone of the Enum with some items removed.
Parameters
----------
*items
The items to remove remove from the new enum.
Returns
-------
result : Enum
A new enum object which contains all of the original items
but with the given items removed.
"""
newitems = tuple(i for i in self.items if i not in items)
if len(newitems) == 0:
raise ValueError('an Enum requires at least 1 item')
clone = self.clone()
clone.set_default_value_mode(DefaultValue.Static, newitems[0])
clone.set_validate_mode(Validate.Enum, newitems)
return clone
def __call__(self, item):
""" Create a clone of the Enum item with a new default.
Parameters
----------
item : object
The item to use as the Enum default. The item must be one
of the valid enum items.
"""
if item not in self.items:
raise TypeError('invalid enum value')
clone = self.clone()
clone.set_default_value_mode(DefaultValue.Static, item)
return clone