Overload 3-arg * (#266)

* Overload 3-arg *

* Update runtests.jl

* Remove `@views` for more reliable coverage

Project.toml

@@ -1,6 +1,6 @@
 name = "FillArrays"
 uuid = "1a297f60-69ca-5386-bcde-b61e274b549b"
-version = "1.2.0"
+version = "1.2.1"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/fillalgebra.jl

@@ -273,6 +273,23 @@ end
 
 *(a::Adjoint{T, <:AbstractMatrix{T}} where T, b::Zeros{<:Any, 1}) = mult_zeros(a, b)
 
+*(a::AdjointAbsVec{<:Any,<:ZerosVector}, D::Diagonal) = (D*a')'
+*(a::TransposeAbsVec{<:Any,<:ZerosVector}, D::Diagonal) = transpose(D*transpose(a))
+function _triple_zeromul(x, D::Diagonal, y)
+    if !(length(x) == length(D.diag) == length(y))
+        throw(DimensionMismatch("x has length $(length(x)), D has size $(size(D)), and y has $(length(y))"))
+    end
+    zero(promote_type(eltype(x), eltype(D), eltype(y)))
+end
+
+*(x::AdjointAbsVec{<:Any,<:ZerosVector}, D::Diagonal, y::AbstractVector) = _triple_zeromul(x, D, y)
+*(x::TransposeAbsVec{<:Any,<:ZerosVector}, D::Diagonal, y::AbstractVector) = _triple_zeromul(x, D, y)
+*(x::AdjointAbsVec, D::Diagonal, y::ZerosVector) = _triple_zeromul(x, D, y)
+*(x::TransposeAbsVec, D::Diagonal, y::ZerosVector) = _triple_zeromul(x, D, y)
+*(x::AdjointAbsVec{<:Any,<:ZerosVector}, D::Diagonal, y::ZerosVector) = _triple_zeromul(x, D, y)
+*(x::TransposeAbsVec{<:Any,<:ZerosVector}, D::Diagonal, y::ZerosVector) = _triple_zeromul(x, D, y)
+
+
 function *(a::Transpose{T, <:AbstractVector{T}}, b::ZerosVector{T}) where T<:Real
     la, lb = length(a), length(b)
     if la ≠ lb

src/oneelement.jl

@@ -119,12 +119,10 @@ function _mulonel!(C, A, B::OneElementMatrix, alpha::Number, beta::Number)
     if iszero(beta)
         C .= zero(eltype(C))
     else
-        @views begin
-            C[:, 1:B.ind[2]-1] .*= beta
-            C[:, B.ind[2]+1:end] .*= beta
-        end
+        view(C, :, 1:B.ind[2]-1) .*= beta
+        view(C, :, B.ind[2]+1:size(C,2)) .*= beta
     end
-    y = @view C[:, B.ind[2]]
+    y = view(C, :, B.ind[2])
     __mulonel!(y, A, B, alpha, beta)
     C
 end

test/runtests.jl

@@ -593,6 +593,21 @@ end
 
         @test transpose([[1,2]]) * Zeros{SVector{2,Int}}(1) ≡ 0
         @test_broken transpose([[1,2,3]]) * Zeros{SVector{2,Int}}(1)
+
+        @testset "Diagonal mul introduced in v1.9" begin
+            @test Zeros(5)'*Diagonal(1:5) ≡ Zeros(5)'
+            @test transpose(Zeros(5))*Diagonal(1:5) ≡ transpose(Zeros(5))
+            @test Zeros(5)'*Diagonal(1:5)*(1:5) ==
+                (1:5)'*Diagonal(1:5)*Zeros(5) ==
+                transpose(1:5)*Diagonal(1:5)*Zeros(5) ==
+                Zeros(5)'*Diagonal(1:5)*Zeros(5) ==
+                transpose(Zeros(5))*Diagonal(1:5)*Zeros(5) ==
+                transpose(Zeros(5))*Diagonal(1:5)*(1:5)
+
+            @test_throws DimensionMismatch Zeros(6)'*Diagonal(1:5)*Zeros(5)
+            @test_throws DimensionMismatch Zeros(5)'*Diagonal(1:6)*Zeros(5)
+            @test_throws DimensionMismatch Zeros(5)'*Diagonal(1:5)*Zeros(6)
+        end
     end
 
     z1, z2 = Zeros{Float64}(4), Zeros{Int}(4)