A live-action movie version of "All You Need Is Kill" has been released released throughout Japan on July 4, 2014 .co.jp/edgeoftomorrow/) To commemorate that, I wrote the ʻAllYouNeedIsKill` class in Python.
aynik.py
#!/usr/bin/env python3
# vim:fileencoding=utf-8
# Copyright (c) 2014 Masami HIRATA <[email protected]>
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are met:
#
# 1. Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
#
# 2. Redistributions in binary form must reproduce the above copyright
# notice, this list of conditions and the following disclaimer in the
# documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
# POSSIBILITY OF SUCH DAMAGE.
__all__ = ['AllYouNeedIsKill']
class AllYouNeedIsKill:
def __init__(self, iterable):
self._iter_source = iter(iterable)
self._buffer = []
self._iter_buffer = None
def __iter__(self):
return self
def __next__(self):
if self._iter_buffer is not None:
try:
return next(self._iter_buffer)
except StopIteration:
self._iter_buffer = None
value = next(self._iter_source)
self._buffer.append(value)
return value
def rewind(self):
if self._buffer:
self._iter_buffer = iter(self._buffer)
else:
self._iter_buffer = None
def reset(self):
if self._iter_buffer is not None:
self._buffer = list(self._iter_buffer)
self.rewind()
else:
self._buffer = []
ʻThe instance of the AllYouNeedIsKillclass behaves as an iterator with the
rewind ()method for rewinding and the
reset ()` method for starting from the state at the time of execution added to the iterator of the argument object. ..
The sample is below.
>>> from itertools import count # count()Is an iterator that just keeps counting up
>>> from aynik import AllYouNeedIsKill
>>> counter = AllYouNeedIsKill(count(1))
>>> next(counter)
1
>>> next(counter)
2
>>> counter.rewind() #Perform rewind
>>> next(counter) #Rewound so it becomes 1
1
>>> next(counter)
2
>>> counter.reset() #Starting from the current state
>>> next(counter)
3
>>> counter.rewind() #Perform rewind
>>> next(counter) #The return value will be 3 instead of 1
3
>>>
The ʻAllYouNeedIsKill class allows me to handle infinite iterators as well, but it's implemented in a class rather than a function, and it's typed like some tools in the standard library ʻitertools
. Please note that the performance is poor due to not deploying iterators to tuples and the code is not Python-like.
ʻAynik.py` will be released under a two-clause BSD license, so feel free to use it.
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