repoview: move subsettable in a dedicated module
The dictionary got moved in `branchmap` to avoid import cycle. However, we are
about to needs it in repoview too. So we introduce a now module to define that
that mapping.
# repoviewutil.py - constaints data relevant to repoview.py and other module
#
# Copyright 2012 Pierre-Yves David <pierre-yves.david@ens-lyon.org>
# Logilab SA <contact@logilab.fr>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
### Nearest subset relation
# Nearest subset of filter X is a filter Y so that:
# * Y is included in X,
# * X - Y is as small as possible.
# This create and ordering used for branchmap purpose.
# the ordering may be partial
subsettable = {None: 'visible',
'visible-hidden': 'visible',
'visible': 'served',
'served.hidden': 'served',
'served': 'immutable',
'immutable': 'base'}