~bzr-pqm/bzr/bzr.dev

# Copyright (C) 2009, 2010 Canonical Ltd

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program; if not, write to the Free Software

# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

"""Interface thunk for a StaticTuple implementation."""

from __future__ import absolute_import

from bzrlib import debug

try:

    from bzrlib._static_tuple_c import StaticTuple

except ImportError, e:

    from bzrlib import osutils

    osutils.failed_to_load_extension(e)

    from bzrlib._static_tuple_py import StaticTuple

def expect_static_tuple(obj):

    """Check if the passed object is a StaticTuple.

    Cast it if necessary, but if the 'static_tuple' debug flag is set, raise an

    error instead.

    As apis are improved, we will probably eventually stop calling this as it

    adds overhead we shouldn't need.

    """

    if 'static_tuple' not in debug.debug_flags:

        return StaticTuple.from_sequence(obj)

    if type(obj) is not StaticTuple:

        raise TypeError('We expected a StaticTuple not a %s' % (type(obj),))

    return obj

def as_tuples(obj):

    """Ensure that the object and any referenced objects are plain tuples.

    :param obj: a list, tuple or StaticTuple

    :return: a plain tuple instance, with all children also being tuples.

    """

    result = []

    for item in obj:

        if isinstance(item, (tuple, list, StaticTuple)):

            item = as_tuples(item)

        result.append(item)

    return tuple(result)