Overload axes for Symmetric/Triangular of a LayoutArray (#95)

* Overload axes for Symmetric/Triangular of a LayoutArray

* Update test_layoutarray.jl

* Update ArrayLayouts.jl

* Revert "Update ArrayLayouts.jl"

This reverts commit 34640fb.

Author: dlfivefifty

Project.toml

@@ -1,7 +1,7 @@
 name = "ArrayLayouts"
 uuid = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
 authors = ["Sheehan Olver <[email protected]>"]
-version = "0.8.5"
+version = "0.8.6"
 
 [deps]
 FillArrays = "1a297f60-69ca-5386-bcde-b61e274b549b"

src/diagonal.jl

@@ -1,4 +1,3 @@
-
 ###
 # Lmul
 ####

src/memorylayout.jl

@@ -693,3 +693,23 @@ function colsupport(::HermitianLayout, A, j)
 end
 rowsupport(::Union{SymmetricLayout,HermitianLayout}, A, j) = colsupport(A, j)
 
+
+
+function _sym_axes(A)
+    ax = axes(parent(A),2)
+    (ax, ax)
+end
+
+###
+# axes overloads to support block indexing
+###
+
+axes(A::HermOrSym{<:Any,<:LayoutMatrix}) = _sym_axes(A)
+axes(A::HermOrSym{<:Any,<:SubArray{<:Any,2,<:LayoutMatrix}}) = _sym_axes(A)
+axes(A::AbstractTriangular{<:Any,<:LayoutMatrix}) = axes(parent(A))
+axes(A::AbstractTriangular{<:Any,<:SubArray{<:Any,2,<:LayoutMatrix}}) = axes(parent(A))
+
+function axes(D::Diagonal{<:Any,<:LayoutVector})
+    a = axes(parent(D),1)
+    (a,a)
+end

test/test_layoutarray.jl

@@ -327,6 +327,14 @@ MemoryLayout(::Type{MyVector}) = DenseColumnMajor()
         @test A[6] == ArrayLayouts.layout_getindex(A,6) == A[1,2]
         @test A[1,2] == A[CartesianIndex(1,2)] == ArrayLayouts.layout_getindex(A,CartesianIndex(1,2))
     end
+
+    @testset "structured axes" begin
+        A = MyMatrix(rand(5,5))
+        x = MyVector(rand(5))
+        @test axes(Symmetric(A)) == axes(Symmetric(view(A,1:5,1:5))) == axes(A)
+        @test axes(UpperTriangular(A)) == axes(UpperTriangular(view(A,1:5,1:5))) == axes(A)
+        @test axes(Diagonal(x)) == axes(Diagonal(Vector(x)))
+    end
 end
 
 struct MyUpperTriangular{T} <: AbstractMatrix{T}