On 18 June 2014 19:52, Tim Holy <tim.h...@gmail.com> wrote:
>
> Pontus, if your function call is sometimes returning a range and sometimes
> returning an integer, then you may have a type-stability issue anyway. To make
> it type-stable, you may want to have it return 17:17.
I think I formulated myself rather badly, what I meant was a function
call for the end of the range as in `for i in 1:size(x, 1)`, which I
would more frequently than I would like to admit mess up as `for i in
size(x, 1)`.
> Regarding integers-as-iterables, I think the issue is that it makes it much
> easier to write generic code. For example:
>
> function twoloops(index1, index2)
> for i2 in index2
> for i1 in index1
> println(i1, " ", i2)
> end
> end
> end
>
> This code works for all of these:
> twoloops(1:2, 1:3)
> twoloops(5, 1:3)
> twoloops(6:8, 4)
>
> If integers weren't iterables, either one would force the user to call this as
> twoloops(1:2, 1:3)
> twoloops(5:5, 1:3)
> twoloops(6:8, 4:4)
>
> or define functions of different signatures
> twoloops(index1::AbstractVector, index2::AbstractVector)
> twoloops(index1::Real, index2::AbstractVector)
> twoloops(index1::AbstractVector, index2::Real)
Indeed, that is rather neat. While I would favour safety over brevity
in this case (maybe even for most cases, there is still a bit of a
Pythonista somewhere in there), I can certainly see the other side of
the argument here. Thanks to both Tim and Ivar for helping me out with
this one.
Pontus
