A[Block.(1:3)] should return a BlockArray (#122)

* A[Block.(1:3)] should return a BlockArray

* Update Project.toml

Author: dlfivefifty

Project.toml

@@ -1,14 +1,14 @@
 name = "BlockArrays"
 uuid = "8e7c35d0-a365-5155-bbbb-fb81a777f24e"
-version = "0.12.7"
+version = "0.12.8"
 
 [deps]
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
 Compat = "34da2185-b29b-5c13-b0c7-acf172513d20"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
 
 [compat]
-ArrayLayouts = "0.3.2"
+ArrayLayouts = "0.3.4"
 Compat = "2.2, 3"
 julia = "1.1"
 

src/BlockArrays.jl

@@ -38,7 +38,7 @@ import LinearAlgebra: lmul!, rmul!, AbstractTriangular, HermOrSym, AdjOrTrans,
 import ArrayLayouts: _fill_lmul!, MatMulVecAdd, MatMulMatAdd, MatLmulVec, MatLdivVec,
                         materialize!, MemoryLayout, sublayout, transposelayout, conjlayout, 
                         triangularlayout, triangulardata, _inv, _copyto!, axes_print_matrix_row,
-                        colsupport, rowsupport
+                        colsupport, rowsupport, sub_materialize
 
 if !@isdefined(only)
     using Compat: only

src/blocklinalg.jl

@@ -42,6 +42,8 @@ function rowsupport(::BlockLayout, A, k)
     axes(A,2)[Block.(JR)]
 end
 
+
+
 similar(M::MulAdd{<:AbstractBlockLayout,<:AbstractBlockLayout}, ::Type{T}, axes) where {T,N} =
     similar(BlockArray{T}, axes)
 
@@ -57,6 +59,9 @@ sublayout(BL::BlockLayout{MLAY,BLAY}, ::Type{<:Tuple{BlockSlice1,<:BlockSlice{Bl
 sublayout(BL::BlockLayout{MLAY,BLAY}, ::Type{<:Tuple{<:BlockSlice{BlockRange{1,Tuple{II}}},BlockSlice1}}) where {MLAY,BLAY,II} =
     BlockLayout{typeof(sublayout(MLAY(),Tuple{II,Int})), BLAY}()
 
+# materialize views, used for `getindex`
+sub_materialize(::AbstractBlockLayout, V, _) = BlockArray(V)
+sub_materialize(::AbstractStridedLayout, V, ::Tuple{<:BlockedUnitRange}) = PseudoBlockArray(V)
 
 conjlayout(::Type{T}, ::BlockLayout{MLAY,BLAY}) where {T<:Complex,MLAY,BLAY} = BlockLayout{MLAY,typeof(conjlayout(T,BLAY()))}()
 conjlayout(::Type{T}, ::BlockLayout{MLAY,BLAY}) where {T<:Real,MLAY,BLAY} = BlockLayout{MLAY,BLAY}()

src/views.jl

@@ -156,16 +156,16 @@ const BlockSlice1 = BlockSlice{Block{1,Int},UnitRange{Int}}
 block(A::BlockSlice) = block(A.block)
 block(A::Block) = A
 
-getblock(A::SubArray{<:Any,N,<:Any,NTuple{N,BlockSlice1}}) where N = 
+getblock(A::SubArray{<:Any,N,<:Any,NTuple{N,BlockSlice1}}) where N =
     getblock(parent(A), Int.(block.(parentindices(A)))...)
 getblock(A::Adjoint, k::Int, j::Int) = getblock(parent(A), j, k)'
 getblock(A::Transpose, k::Int, j::Int) = transpose(getblock(parent(A), j, k))
 
-strides(A::SubArray{<:Any,N,<:BlockArray,NTuple{N,BlockSlice1}}) where N = 
+strides(A::SubArray{<:Any,N,<:BlockArray,NTuple{N,BlockSlice1}}) where N =
     strides(getblock(A))
 
 for Adj in (:Transpose, :Adjoint)
-    @eval strides(A::SubArray{<:Any,N,<:$Adj{<:Any,<:BlockArray},NTuple{N,BlockSlice1}}) where N = 
+    @eval strides(A::SubArray{<:Any,N,<:$Adj{<:Any,<:BlockArray},NTuple{N,BlockSlice1}}) where N =
         strides(getblock(A))
 end
 
@@ -175,3 +175,5 @@ unsafe_convert(::Type{Ptr{T}}, V::SubArray{T, N, <:Any, <:NTuple{N, BlockSlice1}
 
 unsafe_convert(::Type{Ptr{T}}, V::SubArray{T,N,PseudoBlockArray{T,N,AT},<:Tuple{Vararg{BlockOrRangeIndex}}}) where {T,N,AT} =
     unsafe_convert(Ptr{T}, V.parent) + (Base.first_index(V)-1)*sizeof(T)
+
+

test/test_blockviews.jl

@@ -165,4 +165,13 @@ using BlockArrays, Test, Base64
             @test stringmime("text/plain", W) == "3×1 view(::BlockArray{$Int,2,Array{Array{$Int,2},2},Tuple{BlockedUnitRange{Array{$Int,1}},BlockedUnitRange{Array{$Int,1}}}}, BlockSlice(Block{1,$Int}[Block(1), Block(2)],1:1:3), BlockSlice(Block(1),1:1)) with eltype $Int with indices 1:1:3×Base.OneTo(1):\n 1\n ─\n 4\n 7"
         end
     end
+
+    @testset "getindex with BlockRange" begin
+        A = BlockArray(randn(6), 1:3)
+        @test A[Block.(2:3)] isa BlockArray
+        @test A[Block.(2:3)] == A[2:end]
+        A = PseudoBlockArray(randn(6), 1:3)
+        @test A[Block.(2:3)] isa PseudoBlockArray
+        @test A[Block.(2:3)] == A[2:end]
+    end
 end