Wow, you're right, that is a more serious bug.
On Thursday, 22 October 2015 02:29:13 UTC-5, andy hayden wrote:
>
> > I don't really understand why you can't just use the StepRange for
> everything
>
> You could. However, you can be more efficient by having special types
> (e.g. with UnitRange you don't need to check the steps).
>
> > `findin(::UnitRange, ::UnitRange)` returns another UnitRange
>
> This seems good.
>
> > `findin(::StepRange, ::StepRange)` returns an array of the indices
>
> You might be able to do some maths here to return a StepRange... at least
> for Integers:
>
> function Base.findin{T <: Integer}(a::StepRange{T}, b::StepRange{T})
> start = ??
> step = b.step รท gcd(a.step, b.step)
> stop = max(a.stop, b.stop)
> start:step:stop
> end
>
> but I 'm not sure this is possible with floats...
>
> Looking in the source mentioning UnitRange here's a more serious bug:
> https://github.com/JuliaLang/julia/blob/e16c6784e1ba6f24b6faf0d282c78d8c14a1fbb3/base/array.jl#L866
>
> julia> findin([5.2, 3.3], 3:20)
> 2-element Array{Int64,1}:
> 1
> 2
>
> julia> findin([5.2, 3.3], 3:1:20)
> 0-element Array{Int64,1}
>
> !
>
> On Wednesday, 21 October 2015 19:59:20 UTC-7, Rory Finnegan wrote:
>>
>> Hi folks,
>>
>> I just had a couple questions about ranges that maybe someone can answer.
>>
>>
>> 1) Why are there so many Range types? There is a UnitRange (start, stop),
>> a StepRange (start, step, stop), and a FloatRange(start, step, length,
>> divisor), but I don't really understand why you can't just use the
>> StepRange for everything. Maybe I'm just missing some obvious use cases,
>> but this seems to lead to inconsistent or confusing behaviour like the 1 in
>> my second question.
>>
>> 2) `findin` seems to have inconsistent behaviour for ranges depending on
>> types in the ranges. `findin(::UnitRange, ::UnitRange)` returns another
>> UnitRange, but `findin(::StepRange, ::StepRange)` returns an array of the
>> indices. Is there some reason that these shouldn't be consistent?
>>
>> Ex:
>> ```
>> julia> findin(1:10, 2:5)
>> 2:5
>>
>> julia> findin(1:1:10, 2:2:5)
>> 2-element Array{Int64,1}:
>> 2
>> 4
>>
>> julia> r1 = DateTime(now())-Dates.Day(60):DateTime(now())
>> 2015-08-22T19:07:47:1 day:2015-10-21T19:07:47
>>
>> julia> r2 = r1[1:20]
>> 2015-08-22T19:07:47:1 day:2015-09-10T19:07:47
>>
>> julia> findin(r1, r2)
>> 20-element Array{Int64,1}:
>> 1
>> 2
>> 3
>> 4
>> 5
>> 6
>> 7
>> 8
>> 9
>> 10
>> 11
>> 12
>> 13
>> 14
>> 15
>> 16
>> 17
>> 18
>> 19
>> 20
>> ```
>>
>
