make issparse handle nested wrappers

JuliaLang · Jan 8, 2020 · 922a031 · 922a031
1 parent 9c96131
commit 922a031
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Showing 2 changed files with 29 additions and 25 deletions.
diff --git a/stdlib/SparseArrays/src/abstractsparse.jl b/stdlib/SparseArrays/src/abstractsparse.jl
@@ -50,17 +50,13 @@ julia> issparse(Array(sv))
 false
 ```
 """
-issparse(A::AbstractArray) = false
 issparse(S::AbstractSparseArray) = true
-issparse(S::LinearAlgebra.Adjoint{<:Any,<:AbstractSparseArray}) = true
-issparse(S::LinearAlgebra.Transpose{<:Any,<:AbstractSparseArray}) = true
-
-issparse(S::LinearAlgebra.Symmetric{<:Any,<:AbstractSparseMatrix}) = true
-issparse(S::LinearAlgebra.Hermitian{<:Any,<:AbstractSparseMatrix}) = true
-issparse(S::LinearAlgebra.LowerTriangular{<:Any,<:AbstractSparseMatrix}) = true
-issparse(S::LinearAlgebra.UnitLowerTriangular{<:Any,<:AbstractSparseMatrix}) = true
-issparse(S::LinearAlgebra.UpperTriangular{<:Any,<:AbstractSparseMatrix}) = true
-issparse(S::LinearAlgebra.UnitUpperTriangular{<:Any,<:AbstractSparseMatrix}) = true
+function SparseArrays.issparse(x::AbstractArray)
+    p = parent(x)
+    # Note: For non-wrapper arrays it is defined that `parent(x)===x`, so we use that to check
+    iswrapper = p !== x
+    return iswrapper ? issparse(p) : false
+end
 
 indtype(S::AbstractSparseArray{<:Any,Ti}) where {Ti} = Ti
 

diff --git a/stdlib/SparseArrays/test/sparse.jl b/stdlib/SparseArrays/test/sparse.jl
@@ -2039,21 +2039,29 @@ end
 end
 
 @testset "issparse for specialized matrix types" begin
-    m = sprand(10, 10, 0.1)
-    @test issparse(Symmetric(m))
-    @test issparse(Hermitian(m))
-    @test issparse(LowerTriangular(m))
-    @test issparse(LinearAlgebra.UnitLowerTriangular(m))
-    @test issparse(UpperTriangular(m))
-    @test issparse(LinearAlgebra.UnitUpperTriangular(m))
-    @test issparse(adjoint(m))
-    @test issparse(transpose(m))
-    @test issparse(Symmetric(Array(m))) == false
-    @test issparse(Hermitian(Array(m))) == false
-    @test issparse(LowerTriangular(Array(m))) == false
-    @test issparse(LinearAlgebra.UnitLowerTriangular(Array(m))) == false
-    @test issparse(UpperTriangular(Array(m))) == false
-    @test issparse(LinearAlgebra.UnitUpperTriangular(Array(m))) == false
+    wraps = [
+        Symmetric, Hermitian, Diagonal,
+        LowerTriangular, LinearAlgebra.UnitLowerTriangular,
+        UpperTriangular, LinearAlgebra.UnitUpperTriangular,
+        adjoint, transpose, x->view(x, :, :),
+    ]
+
+    function test_all(mat, expected)
+        @test issparse(mat) == expected
+        for w1 in wraps
+            @test issparse(w1(mat)) == expected
+        end
+        for (w1,w2) in Iterators.product(wraps, wraps)
+            @test issparse(w1(w2(mat))) == expected
+        end
+        for (w1,w2,w3) in Iterators.product(wraps, wraps, wraps)
+            @test issparse(w1(w2(w3(mat)))) == expected
+        end
+    end
+
+    test_all(sprand(10, 10, 0.1), true)
+    test_all((1+im) .* sprand(10, 10, 0.1), true)
+    test_all(rand(10,10), false)
 end
 
 @testset "issparse for sparse vectors #34253" begin