[Numpy-discussion] Proposed Roadmap Overview

Matthew Brett matthew.brett@gmail....
Sat Feb 18 17:04:10 CST 2012


Hi,

On Sat, Feb 18, 2012 at 2:51 PM, Robert Kern <robert.kern@gmail.com> wrote:
> On Sat, Feb 18, 2012 at 22:29, Matthew Brett <matthew.brett@gmail.com> wrote:
>> Hi,
>>
>> On Sat, Feb 18, 2012 at 2:20 PM, Robert Kern <robert.kern@gmail.com> wrote:
>>> On Sat, Feb 18, 2012 at 22:06, Matthew Brett <matthew.brett@gmail.com> wrote:
>>>> Hi,
>>>>
>>>> On Sat, Feb 18, 2012 at 2:03 PM, Robert Kern <robert.kern@gmail.com> wrote:
>
>>>>> Your misunderstanding of what was being discussed. The proposal being
>>>>> discussed is implementing the core of numpy in C++, wrapped in C to be
>>>>> usable as a C library that other extensions can use, and then exposed
>>>>> to Python in an unspecified way. Cython was raised as an alternative
>>>>> for this core, but as Chuck points out, it doesn't really fit. Your
>>>>> assertion that what was being discussed was putting the core in C and
>>>>> using Cython to wrap it was simply a non-sequitur. Discussion of
>>>>> alternatives is fine. You weren't doing that.
>>>>
>>>> You read David's email?  Was he also being annoying?
>>>
>>> Not really, because he was responding on-topic to the bizarro-branch
>>> of the conversation that you spawned about the merits of moving from
>>> hand-written C extensions to a Cython-wrapped C library. Whatever
>>> annoyance his email might inspire is your fault, not his. The
>>> discussion was about whether to use C++ or Cython for the core. Chuck
>>> argued that Cython was not a suitable implementation language for the
>>> core. You responded that his objections to Cython didn't apply to what
>>> you thought was being discussed, using Cython to wrap a pure-C
>>> library. As Pauli (Wolfgang, not our Pauli) once phrased it, you were
>>> "not even wrong". It's hard to respond coherently to someone who is
>>> breaking the fundamental expectations of discourse. Even I had to
>>> stare at the thread for a few minutes to figure out where things went
>>> off the rails.
>>
>> I'm sorry but this seems to me to be aggressive, offensive, and unjust.
>>
>> The discussion was, from the beginning, mainly about the relative
>> benefits of rewriting the core with C / Cython, or C++.
>>
>> I don't think anyone was proposing writing every line of the numpy
>> core in Cython.  Ergo (sorry to use the debating term), the proposal
>> to use Cython was always to take some of the higher level code out of
>> C and leave some of it in C.   It does indeed make the debate
>> ridiculous to oppose a proposal that no-one has made.
>>
>> Now I am sure it is obvious to you, that the proposal to refactor the
>> current C code to into low-level C libraries, and higher level Cython
>> wrappers, is absurd and off the table.  It isn't obvious to me.  I
>> don't think I broke a fundamental rule of polite discourse to clarify
>> that is what I meant,
>
> It's not off the table, but it's not what this discussion was about.

I beg to differ - which was why I replied the way I did.  As I see it
the two proposals being discussed were:

1) C++ rewrite of C core
2) Refactor current C core into C / Cython

I think you can see from David's reply that that was also his
understanding.  Of course you could use Cython to interface to the
'core' in C or the 'core' in C++, but the difference would be, that
some of the stuff in C++ for option 1) would be in Cython, in option
2).

Now you might be saying, that you believe the discussion was only ever
about whether the non-Cython bits would be in C or C++.  That would
indeed make sense of your lack of interest in discussion of Cython.  I
think you'd be hard pressed to claim it was only me discussing Cython
though.

Chuck was pointing out that it was completely ridiculous trying to
implement the entire core in Cython.  Yes it is.  As no-one has
proposed that, it seems to me only reasonable to point out what I
meant, in the interests of productive discourse.

Best,

Matthew


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