#!/usr/bin/env python
 
#  Copyright (c) 2005 Gavin E. Crooks <gec@threeplusone.com>
#
#  This software is distributed under the MIT Open Source License.
#  <http://www.opensource.org/licenses/mit-license.html>
#
#  Permission is hereby granted, free of charge, to any person obtaining a 
#  copy of this software and associated documentation files (the "Software"),
#  to deal in the Software without restriction, including without limitation
#  the rights to use, copy, modify, merge, publish, distribute, sublicense,
#  and/or sell copies of the Software, and to permit persons to whom the
#  Software is furnished to do so, subject to the following conditions:
#
#  The above copyright notice and this permission notice shall be included
#  in all copies or substantial portions of the Software.
#
#  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 
#  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 
#  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
#  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
#  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
#  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 
#  THE SOFTWARE.
#

"""Null sequence IO. Acts like /dev/null. Read returns empty sequences or sequence lists, writes do nothing."""
from __future__ import absolute_import

from ..seq import Seq, SeqList

names = ()
extensions = ()

def read(fin, alphabet=None):       
    assert fin is not None    # Do something with arguments to quiet pychecker
    if alphabet is not None : pass
    return SeqList([])

def iterseq(fin, alphabet=None) :
    assert fin is not None
    if alphabet is not None : pass
    yield Seq('')
    return

def write(fout, seqs): 
    assert fout is not None
    assert seqs is not None
    return

    
def writeseq(fout, seq):
    assert fout is not None
    assert seq is not None
    return