# [julia-users] Re: Zero indexed arrays

`You might get some ideas here https://github.com/alsam/OffsetArrays.jl`
```
On Saturday, October 8, 2016 at 6:39:19 PM UTC+2, Brian Rogoff wrote:
>
>
>
> Hi,
>     I saw in the release notes that Julia added support for different
> array indexing methods. I decided to try my hand at implementing zero
> indexed vectors, and started with the instructions here
> http://docs.julialang.org/en/latest/devdocs/offset-arrays/ I found this
> part of the documentation to be unhelpful compared to other parts of the
> Julia docs (is that just me?), but with a bit of hacking I came up with this
>
> immutable ZeroIndexedVector{T} <: AbstractArray{T, 1}
>     data::Array{T,1}
> end
>
> Base.linearindices{T}(A::ZeroIndexedVector{T}) = 0:(length(A.data)-1)
> Base.getindex{T}(A::ZeroIndexedVector{T}, i::Int) = A.data[i + 1]
> Base.setindex!{T}(A::ZeroIndexedVector{T}, v, i::Int) = (A.data[i + 1] = v)
> Base.indices{T}(A::ZeroIndexedVector{T}) =
>     (0:(length(A.data)-1),)
>
> Base.endof{T}(A::ZeroIndexedVector{T}) = length(A.data) - 1
> Base.show{T}(A::ZeroIndexedVector{T}) = show(A.data)
> function Base.display{T}(A::ZeroIndexedVector{T})
>     @printf("%d-element ZeroIndexedVector{%s, 1}:\n",
>             length(A.data),
>             string(T))
>     for elt in A.data
>        @printf("%s\n", string(elt))
>     end
> end
>
> Apart from some obvious failings (eg, not copying he backing array) it
> seems to work. What's the best way to write this code? How does one extend
> this to multidimensional arrays? IMO, the explanation of how to do these
> two things would have served as good examples on the doc page.
>
> -- Brian
>
```