#!/usr/bin/env python
# -*- coding: utf-8 -*-

# Copyright 2013 David Marek
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import numpy as np

from itertools import repeat
from .factor import Factor, to_log


def constant_factory(value):
    """Create function returning constant value."""
    return repeat(value).next


def constant_factor(variables, variables_dict, length, logarithmetic=True):
    if logarithmetic:
        factor = Factor(variables, variables_dict, to_log(np.ones(length)), logarithmetic)
    else:
        factor = Factor(variables, variables_dict, np.ones(length), logarithmetic)
    return factor
