_scons_itertools.py
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上传日期:2018-11-18
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- #
- # Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008 The SCons Foundation
- #
- # 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.
- #
- __revision__ = "src/engine/SCons/compat/_scons_itertools.py 3057 2008/06/09 22:21:00 knight"
- __doc__ = """
- Implementations of itertools functions for Python versions that don't
- have iterators.
- These implement the functions by creating the entire list, not returning
- it element-by-element as the real itertools functions do. This means
- that early Python versions won't get the performance benefit of using
- the itertools, but we can still use them so the later Python versions
- do get the advantages of using iterators.
- Because we return the entire list, we intentionally do not implement the
- itertools functions that "return" infinitely-long lists: the count(),
- cycle() and repeat() functions. Other functions below have remained
- unimplemented simply because they aren't being used (yet) and it wasn't
- obvious how to do it. Or, conversely, we only implemented those functions
- that *were* easy to implement (mostly because the Python documentation
- contained examples of equivalent code).
- Note that these do not have independent unit tests, so it's possible
- that there are bugs.
- """
- def chain(*iterables):
- result = []
- for x in iterables:
- result.extend(list(x))
- return result
- def count(n=0):
- # returns infinite length, should not be supported
- raise NotImplementedError
- def cycle(iterable):
- # returns infinite length, should not be supported
- raise NotImplementedError
- def dropwhile(predicate, iterable):
- result = []
- for x in iterable:
- if not predicate(x):
- result.append(x)
- break
- result.extend(iterable)
- return result
- def groupby(iterable, *args):
- raise NotImplementedError
- def ifilter(predicate, iterable):
- result = []
- if predicate is None:
- predicate = bool
- for x in iterable:
- if predicate(x):
- result.append(x)
- return result
- def ifilterfalse(predicate, iterable):
- result = []
- if predicate is None:
- predicate = bool
- for x in iterable:
- if not predicate(x):
- result.append(x)
- return result
- def imap(function, *iterables):
- return apply(map, (function,) + tuple(iterables))
- def islice(*args, **kw):
- raise NotImplementedError
- def izip(*iterables):
- return apply(zip, iterables)
- def repeat(*args, **kw):
- # returns infinite length, should not be supported
- raise NotImplementedError
- def starmap(*args, **kw):
- raise NotImplementedError
- def takewhile(predicate, iterable):
- result = []
- for x in iterable:
- if predicate(x):
- result.append(x)
- else:
- break
- return result
- def tee(*args, **kw):
- raise NotImplementedError