XXX in your questions = chain.
Or more clearly:
julia> stream = chain([1,2,3,4,5])
Iterators.Chain(Any[[1,2,3,4,5]])
julia> collect(take(stream, 3))
3-element Array{Any,1}:
1
2
3
On Monday, November 9, 2015 at 7:47:51 PM UTC+2, andrew cooke wrote:
>
>
> hmmm. maybe i'm doing it wrong as that only gives a factor of 2 speedup.
>
> anyway, it's all i need for now, i may return to this later.
>
> thanks again,
> andrew
>
> On Monday, 9 November 2015 14:11:55 UTC-3, andrew cooke wrote:
>>
>>
>> yes, i'm about to do it for arrays (i don't care about performance right
>> now, but i want to implement read with type conversion and so need the
>> types).
>>
>> On Monday, 9 November 2015 11:20:47 UTC-3, Yichao Yu wrote:
>>>
>>> On Mon, Nov 9, 2015 at 8:04 AM, andrew cooke <and...@acooke.org> wrote:
>>> >
>>> > https://github.com/andrewcooke/StatefulIterators.jl
>>>
>>> FYI, one way to make this more efficient is to parametrize the
>>> iterator. You could easily do this for Array's. In the more general
>>> case, you needs type inference to get the type right for a
>>> non-type-stable iterator (iterator with a type unstable index...) but
>>> it's generally a bad idea to write code that calls type inference
>>> directly.
>>>
>>> >
>>> >
>>> > On Monday, 9 November 2015 06:24:14 UTC-3, andrew cooke wrote:
>>> >>
>>> >> thanks!
>>> >>
>>> >> On Sunday, 8 November 2015 22:40:53 UTC-3, Yichao Yu wrote:
>>> >>>
>>> >>> On Sun, Nov 8, 2015 at 8:11 PM, andrew cooke <and...@acooke.org>
>>> wrote:
>>> >>> > I'd like to be able to use take() and all the other iterator tools
>>> with
>>> >>> > a
>>> >>> > stream of data backed by an array (or string).
>>> >>> >
>>> >>> > By that I mean I'd like to be able to do something like:
>>> >>> >
>>> >>> >> stream = XXX([1,2,3,4,5])
>>> >>> >> collect(take(stream, 3))
>>> >>> > [1,2,3]
>>> >>> >> collect(take(stream, 2))
>>> >>> > [4,5]
>>> >>> >
>>> >>> > Is this possible? I can find heavyweight looking streams for IO,
>>> and I
>>> >>> > can
>>> >>> > find lightweight iterables without state. But I can't seem to
>>> find the
>>> >>> > particular mix described above.
>>> >>>
>>> >>> Jeff's conclusion @ JuliaCon is that it seems impossible to
>>> implement
>>> >>> this (stateful iterator) currently in a generic and performant way
>>> so
>>> >>> I doubt you will find it in a generic iterator library (that works
>>> not
>>> >>> only on arrays). A version that works only on Arrays should be
>>> simple
>>> >>> enough to implement and doesn't sound useful enough to be in an
>>> >>> exported API so I guess you probably should just implement your own.
>>> >>>
>>> >>> Ref
>>> >>>
>>> https://groups.google.com/forum/?fromgroups=#!searchin/julia-users/iterator/julia-users/t4ZieI2_iwI/3NTw1k406qkJ
>>>
>>> >>>
>>> >>> >
>>> >>> > (I think I can see how to write it myself; I'm asking if it
>>> already
>>> >>> > exists -
>>> >>> > seems like it should, but I can't find the right words to search
>>> for).
>>> >>> >
>>> >>> > Thanks,
>>> >>> > Andrew
>>> >>> >
>>>
>>
