# Copyright (c) 2021 PaddlePaddle Authors. All Rights Reserved.
#
# 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.
# Modified from espnet(https://github.com/espnet/espnet)
"""Repeat the same layer definition."""
import paddle


class MultiSequential(paddle.nn.Sequential):
    """Multi-input multi-output paddle.nn.Sequential."""

    def forward(self, *args):
        """Repeat."""
        for m in self:
            args = m(*args)
        return args


def repeat(N, fn):
    """Repeat module N times.

    Parameters
    ----------
    N : int
        Number of repeat time.
    fn : Callable
        Function to generate module.

    Returns
    ----------
    MultiSequential
        Repeated model instance.
    """
    return MultiSequential(* [fn(n) for n in range(N)])