static indexing on sparse array doesn't work anymore

[Roger-luo]

not sure what is changed, but is causing QuantumBFS/tutorials#17

MWE:

julia> using StaticArrays, SparseArrays

julia> st = sprand(16, 1, 0.1);

julia> I = @SVector [2, 4];

julia> st[I, 1] = st[I, 1]
ERROR: MethodError: no method matching length(::StaticArrays.StaticIndexing{SVector{2, Int64}})
Closest candidates are:
  length(::Union{Base.KeySet, Base.ValueIterator}) at abstractdict.jl:58
  length(::Union{LinearAlgebra.Adjoint{T, var"#s6"} where var"#s6"<:Union{StaticVector{var"#s1", T} where var"#s1", StaticMatrix{var"#s4", var"#s5", T} where {var"#s4", var"#s5"}}, LinearAlgebra.Diagonal{T, var"#s13"} where var"#s13"<:(StaticVector{var"#s14", T} where var"#s14"), LinearAlgebra.Hermitian{T, var"#s10"} where var"#s10"<:(StaticMatrix{var"#s11", var"#s12", T} where {var"#s11", var"#s12"}), LinearAlgebra.LowerTriangular{T, var"#s18"} where var"#s18"<:(StaticMatrix{var"#s19", var"#s20", T} where {var"#s19", var"#s20"}), LinearAlgebra.Symmetric{T, var"#s7"} where var"#s7"<:(StaticMatrix{var"#s8", var"#s9", T} where {var"#s8", var"#s9"}), LinearAlgebra.Transpose{T, var"#s1"} where var"#s1"<:Union{StaticVector{var"#s1", T} where var"#s1", StaticMatrix{var"#s4", var"#s5", T} where {var"#s4", var"#s5"}}, LinearAlgebra.UnitLowerTriangular{T, var"#s24"} where var"#s24"<:(StaticMatrix{var"#s25", var"#s26", T} where {var"#s25", var"#s26"}), LinearAlgebra.UnitUpperTriangular{T, var"#s21"} where var"#s21"<:(StaticMatrix{var"#s22", var"#s23", T} where {var"#s22", var"#s23"}), LinearAlgebra.UpperTriangular{T, var"#s15"} where var"#s15"<:(StaticMatrix{var"#s16", var"#s17", T} where {var"#s16", var"#s17"}), StaticVector{var"#s26", T} where var"#s26", StaticMatrix{var"#s5", var"#s4", T} where {var"#s5", var"#s4"}, StaticArray{var"#s26", T, N} where {var"#s26"<:Tuple, N}} where T) at /Users/roger/.julia/packages/StaticArrays/LJQEe/src/abstractarray.jl:1
  length(::Union{LinearAlgebra.Adjoint{T, S}, LinearAlgebra.Transpose{T, S}} where {T, S}) at /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/LinearAlgebra/src/adjtrans.jl:207
  ...
Stacktrace:
 [1] setindex!(A::SparseMatrixCSC{Float64, Int64}, V::SparseVector{Float64, Int64}, Ix::SVector{2, Int64}, Jx::Int64)
   @ SparseArrays /Users/julia/buildbot/worker/package_macos64/build/usr/share/julia/stdlib/v1.6/SparseArrays/src/sparsematrix.jl:2798
 [2] top-level scope
   @ REPL[10]:1

[Roger-luo]

it works on normal vectors, I assume static vector should work on this case with iterate, length interface etc. defeind?

[andyferris]

I’m surprised to see 'StaticIndexing` being intercepted outside this package. I thought it was meant to be internal?

If not then it probably needs to be a valid set of array indices (like an AbstractArray).

I suppose this might be the nature of setindex! though?

[mateuszbaran]

StaticIndexing can't be considered internal since it is returned by a method extending a function from Base.to_indices. Currently StaticArrays breaks the rules described here: https://docs.julialang.org/en/v1/base/arrays/#Base.to_indices. I think StaticIndexing should be <:AbstractVector and support length and getindex operations.

[andyferris]

Yeah that does sound good.