DArray: Add view ctor

Author: jpsamaroo

src/array/alloc.jl

@@ -81,6 +81,15 @@ function Base.zero(x::DArray{T,N}) where {T,N}
     return _to_darray(a)
 end
 
+function Base.view(A::AbstractArray{T,N}, p::Blocks{N}) where {T,N}
+    d = ArrayDomain(Base.index_shape(A))
+    dc = partition(p, d)
+    # N.B. We use `tochunk` because we only want to take the view locally, and
+    # taking views should be very fast
+    chunks = [tochunk(view(A, x.indexes...)) for x in dc]
+    return DArray(T, d, dc, chunks, p)
+end
+
 function sprand(p::Blocks, m::Integer, n::Integer, sparsity::Real)
     s = rand(UInt)
     f = function (idx, t,sz)

test/array.jl

@@ -38,6 +38,16 @@ end
     @test r[1:10] != r[11:20]
 end
 
+@testset "view" begin
+    A = rand(64, 64)
+    DA = view(A, Blocks(8, 8))
+    @test collect(DA) == A
+    @test size(DA) == (64, 64)
+    A_v = fetch(first(DA.chunks))
+    @test A_v isa SubArray
+    @test A_v == A[1:8, 1:8]
+end
+
 @testset "map" begin
     X1 = ones(Blocks(10, 10), 100, 100)
     X2 = map(x->x+1, X1)