[Cython] New function (pointer) syntax.

[Dima Pasechnik]

On 10 November 2014 20:23, Robert Bradshaw <robertwb at gmail.com> wrote:
> On Mon, Nov 10, 2014 at 6:25 AM, Dima Pasechnik <dimpase at gmail.com> wrote:
>> On 2014-11-06, Robert Bradshaw <robertwb at gmail.com> wrote:
>>> I'd like to propose a more pythonic way to declare function pointer
>>> types, namelye
>>>
>>>     type0 (*[ident])(type1, type2, type3)
>>>
>>> would instead become
>>>
>>>     (type1, type2, type3) -> type0 [ident]
>>>
>>> I have a pull request up at https://github.com/cython/cython/pull/333;
>>> what do people think?
>>
>> we had a discussion with Volker about this few weeks ago - in my Cython code I
>> needed to do, as he suggested, a workaround like this:
>>
>>    int* vlamatrix  "(int (*)[])" (int*) # a hack to get int (*)[] through cython
>>
>> This was for 2-dim arrays of variable length, and looks similar to the
>> stuff here.
>>
>> IMHO it would be good to address this, too.
>
> Yeah.
>
>> I'd rather stick to C99 conventions in Cython.
>> To me, using '->' for types looks way too close to what is used, with
>> different semantics,  in functional languages like Haskell or Coq.
>
> Actually, the proposed use of '->' *is* identical to Haskell in
> semantics, i.e. "int -> int" is how you write a function taking and
> returning an int. Of course in Python one has a single argument tuple
> as input rather than currying.

well, I don't really see why ident is put at the end of the statement.
As you know, Haskell-like it would be

ident :: (type1, type2, type3) -> type0

if you work in postscript, then indeed putting ident at the end
would be natural :-)

Dima