A Standard
Andrew Koenig
ark at research.att.com
Mon May 26 13:54:56 EDT 2003
>> What I see in this description is that the Python notion of "sequence
>> types" is decidedly non-sequential, because __getitem__ really takes an
>> arbitrary index as input. So what Python calls a "sequence type" is
>> closest to the C++ notion of a random-access iterator, except that you
>> cannot offset such an iterator by an integer to obtain a new iterator.
>> Such differences can have surprisingly profound effects on programs.
Jay> I thought a Python 'sequence type' was closer to a C notation of an array?
Jay> You can iterate sequentially over a sequence type, but a sequence type,
Jay> but that's really a linear wrapper using a random access mechanism
Right. That's what I meant when I said that Python sequence types are
non-sequential. As far as I can see, Python has no notion to correspond
to the C++ notion of a forward iterator.
Of course, whether it should have such a notion is another matter entirely.
I still think it's an interesting research question.
--
Andrew Koenig, ark at research.att.com, http://www.research.att.com/info/ark
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