[Cython] array expressions

[Robert Bradshaw]

On Sun, Oct 14, 2012 at 6:13 AM, mark florisson
<markflorisson88 at gmail.com> wrote:
> On 14 October 2012 14:05, Stefan Behnel <stefan_ml at behnel.de> wrote:
>> mark florisson, 14.10.2012 13:59:
>>> The problem with minivect as a package is that it caters to different
>>> projects, which have different requirements. Cython and minivect are
>>> quite closely coupled, and any future change, or in the future any
>>> older version may not have the functionality Cython needs, it's not
>>> exactly a stable API at this point.
>>
>> Ok, understood.
>>
>>
>>> For instance Numba needs python
>>> 2.7, whereas Cython needs to be compatible with python 2.4.
>>>
>>> Before releasing minivect I'll verify every time that it doesn't break
>>> Cython, but I currently have no real promises for backwards or forward
>>> compatibility. And that is really because not all use cases have yet
>>> been anticipated, and some really require a change, as I've already
>>> seen with Numba.
>>>
>>> We could list minivect as a dependency, which works for
>>> easy_install/pip users, but I just foresee numerous people running
>>> into problems that didn't install with pip, and I don't think an
>>> exclusion of a 300kb addition is worth any of that.
>>
>> Fine. In that case, I'm for not making minivect a separate package at all
>> but including it directly and considering it a part of Cython (and Numba
>> etc.) until there is enough of an interface to make it a reusable separate
>> package, or at least to support a separate installation and independent
>> update. Basically, if you can't update it separately, there's no use in
>> installing it separately.
>>
>> As long as we handle this so, we should take care to keep the generic parts
>> in their separate package directory and the Cython specific parts in
>> Cython, and try to keep the interface between the two as cleanly separate
>> as possible, so that we can actually reach a point where both have an
>> interface. I would guess that the need to support Numba from the same
>> source base will encourage this kind of separation anyway.
>
> Yes, definitely.
>
>> Note that this means that minivect will fall under the release schedules of
>> Cython and Numba (independently), instead of really having its own releases.
>
> It can have its own releases as well, but currently there isn't much
> point :) Minivect can be developed independent of the releases, since
> Cython and Numba need to explicitly pull in the changes. Let's make a
> habit of squashing the minivect pulls to avoid its history.
>
> I'll also wait for Dag and Robert to see if they have a (final)
> opinion before merging the subtree.

As I mentioned on the pull request, looks good to me. Given the
(somewhat) tight coupling with the AST but the desire to use the
codebase for multiple projects, a subtree seems to make the most sense
(until/if we have some kind of a plugin system).

- Robert