Add BroadcastStyle support for BroadcastArray

Author: DanielVandH

src/lazybroadcasting.jl

@@ -52,6 +52,8 @@ end
 const BroadcastVector{T,F,Args} = BroadcastArray{T,1,F,Args}
 const BroadcastMatrix{T,F,Args} = BroadcastArray{T,2,F,Args}
 
+BroadcastStyle(::Type{<:BroadcastArray{<:Any,N,<:Any,Args}}) where {N,Args<:Tuple} = result_style(LazyArrayStyle{N}(), tuple_type_broadcastlayout(Args))
+
 LazyArray(bc::Broadcasted) = BroadcastArray(bc)
 
 BroadcastArray{T,N,F,Args}(bc::Broadcasted) where {T,N,F,Args} = BroadcastArray{T,N,F,Args}(bc.f,bc.args)

test/broadcasttests.jl

@@ -2,8 +2,9 @@ module BroadcastTests
 
 using LazyArrays, ArrayLayouts, LinearAlgebra, FillArrays, Base64, Test
 using StaticArrays, Tracker
-import LazyArrays: BroadcastLayout, arguments, LazyArrayStyle, sub_materialize, simplifiable
+import LazyArrays: BroadcastLayout, CachedArrayStyle, arguments, LazyArrayStyle, sub_materialize, simplifiable
 import Base: broadcasted
+import Base.Broadcast: BroadcastStyle
 
 using ..InfiniteArrays
 using Infinities
@@ -478,6 +479,13 @@ using Infinities
             @test_throws "MethodError: no method matching _vec_mul_arguments"  LazyArrays._vec_mul_arguments(2, [])
         end
     end
+
+    @testset "BroadcastStyle" begin
+        @test BroadcastStyle(typeof(BroadcastVector(exp, 1:10))) == LazyArrayStyle{1}()
+        @test BroadcastStyle(typeof(BroadcastVector(+, 1:10, cache(1:10)))) == CachedArrayStyle{1}()
+        @test BroadcastStyle(typeof(BroadcastMatrix(*, Accumulate(*, 1:10)', rand(10)'))) == CachedArrayStyle{2}()
+        @test BroadcastStyle(typeof(BroadcastMatrix(*, rand(5, 5)', LazyArrays.CachedArray(rand(5, 5))))) == CachedArrayStyle{2}()
+    end
 end
 
 end #module