diff --git a/src/oneelement.jl b/src/oneelement.jl index d395fa9f..f9d6caf3 100644 --- a/src/oneelement.jl +++ b/src/oneelement.jl @@ -48,14 +48,53 @@ Base.@propagate_inbounds function Base.getindex(A::OneElement{T,N}, kj::Vararg{I end """ - nzind(A::OneElement) + nzind(A::OneElement{T,N}) -> CartesianIndex{N} Return the index where `A` contains a non-zero value. -The indices are not guaranteed to lie within the valid index bounds for `A`, -and if `all(!in.(nzind(A), axes(A)))` then `all(iszero, A)`. + +!!! note + The indices are not guaranteed to lie within the valid index bounds for `A`, + and if `FillArrays.nzind(A) ∉ CartesianIndices(A)` then `all(iszero, A)`. + On the other hand, if `FillArrays.nzind(A) in CartesianIndices(A)` then + `A[FillArrays.nzind(A)] == FillArrays.getindex_value(A)` + +# Examples +```jldoctest +julia> A = OneElement(2, (1,2), (2,2)) +2×2 OneElement{Int64, 2, Tuple{Int64, Int64}, Tuple{Base.OneTo{Int64}, Base.OneTo{Int64}}}: + ⋅ 2 + ⋅ ⋅ + +julia> FillArrays.nzind(A) +CartesianIndex(1, 2) + +julia> A[FillArrays.nzind(A)] +2 +``` +""" +nzind(f::OneElement) = CartesianIndex(f.ind) + """ -nzind(f::OneElement) = f.ind + getindex_value(A::OneElement) + +Return the only non-zero value stored in `A`. +!!! note + If the index at which the value is stored doesn't lie within the valid indices of `A`, then + this returns `zero(eltype(A))`. + +# Examples +```jldoctest +julia> A = OneElement(2, 3) +3-element OneElement{Int64, 1, Tuple{Int64}, Tuple{Base.OneTo{Int64}}}: + ⋅ + 1 + ⋅ + +julia> FillArrays.getindex_value(A) +1 +``` +""" getindex_value(A::OneElement) = all(in.(A.ind, axes(A))) ? A.val : zero(eltype(A)) Base.AbstractArray{T,N}(A::OneElement{<:Any,N}) where {T,N} = OneElement(T(A.val), A.ind, A.axes) diff --git a/test/runtests.jl b/test/runtests.jl index 59594fbd..4c657ff9 100644 --- a/test/runtests.jl +++ b/test/runtests.jl @@ -2044,13 +2044,13 @@ end @testset "OneElement" begin A = OneElement(2, (), ()) - @test FillArrays.nzind(A) == () + @test FillArrays.nzind(A) == CartesianIndex() @test A == Fill(2, ()) @test A[] === 2 e₁ = OneElement(2, 5) @test e₁ == [0,1,0,0,0] - @test FillArrays.nzind(e₁) == (2,) + @test FillArrays.nzind(e₁) == CartesianIndex(2) @test_throws BoundsError e₁[6] f₁ = AbstractArray{Float64}(e₁) @@ -2070,7 +2070,7 @@ end V = OneElement(2, (2,3), (3,4)) @test V == [0 0 0 0; 0 0 2 0; 0 0 0 0] - @test FillArrays.nzind(V) == (2,3) + @test FillArrays.nzind(V) == CartesianIndex(2,3) Vf = AbstractArray{Float64}(V) @test Vf isa OneElement{Float64,2}