view(::AbstractFill, ::Block) (#207)

* view(::AbstractFill, ::Block)

* Generalise fill view special cases

Author: dlfivefifty

src/blocklinalg.jl

@@ -64,7 +64,7 @@ sublayout(BL::BlockLayout{MLAY,BLAY}, ::Type{<:Tuple{Sl,<:BlockSlice{BlockRange{
 sublayout(BL::BlockLayout{MLAY,BLAY}, ::Type{<:Tuple{<:BlockSlice{BlockRange{1,Tuple{II}}},Sl}}) where {MLAY,BLAY,Sl<:Slice,II} =
     BlockLayout{typeof(sublayout(MLAY(),Tuple{II,Sl})), BLAY}()
 sublayout(BL::BlockLayout{MLAY,BLAY}, ::Type{<:Tuple{Sl1,Sl2}}) where {MLAY,BLAY,Sl1<:Slice,Sl2<:Slice,II} =
-    BlockLayout{typeof(sublayout(MLAY(),Tuple{Sl1,Sl2})), BLAY}()    
+    BlockLayout{typeof(sublayout(MLAY(),Tuple{Sl1,Sl2})), BLAY}()
 
 # materialize views, used for `getindex`
 sub_materialize(::AbstractBlockLayout, V, _) = BlockArray(V)
@@ -101,6 +101,13 @@ sub_materialize(::ArrayLayouts.OnesLayout, V, ax::Tuple{<:AbstractUnitRange,<:Bl
 sub_materialize(::ArrayLayouts.ZerosLayout, V, ax::Tuple{<:AbstractUnitRange,<:BlockedUnitRange}) =
     Zeros{eltype(V)}(ax)
 
+@propagate_inbounds Base.view(A::FillArrays.AbstractFill{<:Any,N}, I::Vararg{Union{Real, AbstractArray, Block}, N}) where N =
+    FillArrays._fill_getindex(A, Base.to_indices(A, I)...)
+@propagate_inbounds Base.view(A::FillArrays.AbstractFill{<:Any,N}, I::Block{N}) where N =
+    FillArrays._fill_getindex(A, Base.to_indices(A, (I,))...)
+@propagate_inbounds Base.view(A::FillArrays.AbstractFill{<:Any,1}, I::Block{1}) =
+    FillArrays._fill_getindex(A, Base.to_indices(A, (I,))...)
+
 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}()
 

test/test_blockarrayinterface.jl

@@ -127,15 +127,16 @@ end
 
 @testset "block Fill" begin
     A = Fill(2,(blockedrange([1,2,2]),))
-    @test A[Block(1)] ≡ Fill(2,1)
+    @test A[Block(1)] ≡ view(A,Block(1)) ≡ Fill(2,1)
     @test A[Block.(1:2)] == [2,2,2]
     @test A[Block.(1:2)] isa Fill
+    @test view(A,Block.(1:2)) isa Fill
     @test 2A ≡ Fill(4,axes(A))
 
     F = Fill(2, (blockedrange([1,2,2]),blockedrange(1:3)))
-    @test F[Block(2,2)] ≡ F[Block(2),Block(2)] ≡ Fill(2, 2,2)
-    @test F[Block(2),1:5] ≡ Fill(2, 2,5)
-    @test F[1:5,Block(2)] ≡ Fill(2, 5,2)
+    @test F[Block(2,2)] ≡ view(F,Block(2,2)) ≡ view(F,Block(2),Block(2)) ≡ F[Block(2),Block(2)] ≡ Fill(2, 2,2)
+    @test F[Block(2),1:5] ≡ view(F,Block(2),1:5) ≡ Fill(2, 2,5)
+    @test F[1:5,Block(2)] ≡ view(F,1:5,Block(2)) ≡ Fill(2, 5,2)
     @test F[:,Block(2)] ≡ Fill(2, (axes(F,1),Base.OneTo(2)))
     @test F[Block(2),:] ≡ Fill(2, (Base.OneTo(2),axes(F,2)))
     @test F[Block.(1:2),Block.(1:2)] == Fill(2, (blockedrange([1,2]),blockedrange(1:2)))