WIP: InterlaceLayout

src/interlace.jl

@@ -0,0 +1,19 @@
+struct InterlaceLayout end
+
+reshapedlayout(::ApplyLayout{typeof(vcat)}, _) = InterlaceLayout()
+function arguments(::InterlaceLayout, A::ReshapedArray)
+    args = arguments(ApplyLayout{typeof(Vcat)}(), parent(A))
+    map(_permutedims, args)
+end
+
+function _copyto!(_, ::InterlaceLayout, dest::AbstractVector, A::AbstractVector)
+    args = arguments(InterlaceLayout(), A)
+    _interlace_copyto!(1, length(args), dest, args...)
+end
+
+function _interlace_copyto!(k, st, dest, a, b...)
+    copyto!(view(dest, k:st:length(dest)), a)
+    _interlace_copyto!(k+1, st, dest, b...)
+end
+
+_interlace_copyto!(k, st, dest) = dest

src/lazyconcat.jl

@@ -463,6 +463,8 @@ copy(f::Transpose{<:Any,<:Union{Vcat,Hcat}}) = transpose(copy(parent(f)))
 
 _permutedims(a) = a
 _permutedims(a::AbstractArray) = permutedims(a)
+_permutedims(a::Transpose{<:Number}) = parent(a)
+_permutedims(a::Adjoint{<:Real}) = parent(a)
 
 permutedims(A::Hcat{T}) where T = Vcat{T}(map(_permutedims,A.args)...)
 permutedims(A::Vcat{T}) where T = Hcat{T}(map(_permutedims,A.args)...)
@@ -770,7 +772,7 @@ function rowsupport(lay::ApplyLayout{typeof(hcat)}, M::AbstractArray, k)
 end
 
 include("padded.jl")
-
+include("interlace.jl")
 
 
 ###

test/interlacetests.jl

@@ -0,0 +1,16 @@
+using LazyArrays, ArrayLayouts, Test
+import LazyArrays: InterlaceLayout, arguments
+
+@testset "Interlace" begin
+    n = 10
+    a = 1:n
+    b = n+1:2n
+    A = Vcat(a', b')
+    v = vec(A)
+    @test MemoryLayout(v) isa InterlaceLayout
+    @test arguments(v) == (a,b)
+    @test ArrayLayouts._copyto!(zeros(2n), v) == vec(Matrix(A))
+
+    v = view(A, 1:2n)
+    MemoryLayout(v)
+end

test/runtests.jl

@@ -53,6 +53,7 @@ include("macrotests.jl")
 include("lazymultests.jl")
 include("concattests.jl")
 include("paddedtests.jl")
+include("interlacetests.jl")
 include("broadcasttests.jl")
 include("cachetests.jl")