On Sunday, October 16, 2016 at 4:54:45 PM UTC, Yichao Yu wrote:
>
>
>
> On Sun, Oct 16, 2016 at 12:01 PM, Páll Haraldsson <pall.ha...@gmail.com
> <javascript:>> wrote:
>
>>
>> I was prototyping:
>>
>> julia> a=[1,2,3,1,2]
>>
>> julia> b=[a[i]<a[i+1] for i in 1:length(a)-1]
>> 4-element Array{Bool,1}:
>> true
>> true
>> false
>> true
>>
>>
>> In the beginning when trying stuff out I used:
>>
>> for i in a[1:end-1]
>>
>> or
>>
>> for i in a[2:end]
>>
>> and it got me thinking, end-1 works for any kind of array, but 1 as the
>> start (or 2) is not correct in general. For e.g. general (e.g. zero-based
>> arrays now allowed), what do you do? [If I need all: for i in a just works]
>>
>>
> Not decided yet. Ref https://github.com/JuliaLang/julia/pull/15750
>
Thanks for answering. And from this I see:
https://github.com/JuliaArrays/EndpointRanges.jl
[I'm not clear on (proposed?) "last" vs. "end"; maybe it's just for a demo,
as it would else conflict, if "first" (or "ibegin") and "last" or "iend"
ends up as decided then hopefully soon as a breaking change.. This could
stay in a package forever, but not good as a replacement for "1" is
needed..]
To get one thing clear, "end" continues to work, for the last element, but
since "1" should now be "considered harmful".. "end" may not be very useful
("end:end" is still possible and "end-1:end" etc.. but not much else).
I know about eachindex (or ways for whole arrays/collections), but do not
need each.. What works now to get the second (or first)?
Is something like
view(a, 2:length(a)) # for 1D..
a workaround?
> https://github.com/JuliaLang/julia/pull/15558
<https://github.com/JuliaLang/julia/pull/15558>
> You can always use an assignment in a composite expression.
Not sure what you mean, but may not be important as @inbounds isn't a big
deal [for me] as I think I'll always need a for loop anyway (no big
problem).
