[scalaz seven] Multiply in Type Class Questions

[Anwar Rizal]

Hi,

I notice that  in scalaz seven Monoid has multiply function, that is implemented by calling the replicate function.

Some questions on multiply functions:

1/ If I understand correctly, if I call 3  multiply(10), then append will be called 10 times. Is there a way to override the multiply implementation in the a class instance. For example, in the example 3  multiply(10), I would like to use integer multiplication instead of repetitively calling append ?

2/ Is there any reason why multiply is not defined in Semigroup. Is it because multiply must support 0 as the multiplication factor ? Similarly, I wonder if it is possible to make multiply to support negative number for Group ? 

Thanks,

Anwar .

      

[Runar Bjarnason]

We should probably make it possible to override this function.

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[Anwar Rizal]

Yeah, I think so too.

I would love to have it at Semigroup (that accepts only positive multiplier) and Group (that accepts also negative value).

Anwar.

[Jason Zaugg]

On Sun, Feb 26, 2012 at 10:06 AM, Anwar Rizal <anri...@gmail.com> wrote:
> Yeah, I think so too.
>
> I would love to have it at Semigroup (that accepts only positive multiplier)
> and Group (that accepts also negative value).
>
> Anwar.
>
>
> On Sun, Feb 26, 2012 at 7:06 AM, Runar Bjarnason <runar...@gmail.com>
> wrote:
>>
>> We should probably make it possible to override this function.

That all sounds reasonable. We could make it return Option[A].

-jason

[Anwar Rizal]

OK, I filed an issue here:  :

https://github.com/scalaz/scalaz/issues/77