Please assist with AbstractArray child struct overload

New to Julia
12

It would be nice to have a scalar type for SignedArray perhaps so that just because we index it with a single Integer does not mean that we now get returned an Integer type and lose the associate information in the sign field.

So what I did was create a struct Signed like so:

struct Signed <: Number
    data :: Number
    sign :: String
    function Signed(data :: Number, sign :: String)
        if sign == "signed"
            return new(data, sign)
        elseif sign == "unsigned"
            return new(abs(data), sign)
        end
    end
end

and then change
Base.getindex(sa::SignedArray, I::Integer) = sa.data[I] to Base.getindex(sa::SignedArray, I::Integer) = Signed(sa.data[I], sa.sign)
which kind of works i.e:

R = SignedArray([1,2,3,4], "unsigned")
q = R[2]
println(q)
s = R[1:3]
println(s)

gives

Signed(2, "unsigned")
[Signed(1, "unsigned"), Signed(2, "unsigned"), Signed(3, "unsigned")]

but breaks my setindex! function and I get the following error from running the following code :frowning: :

V = SignedArray(zeros(Int64, 10), "unsigned")
V[3:6] = R
>> MethodError: no method matching Int64(::Signed)

Is this a simple fix or have I opened a can of worms :frowning: ?