Define interface for broadcast expressions with unspecified style (#19)

Author: mtfishman

Project.toml

@@ -1,7 +1,7 @@
 name = "DerivableInterfaces"
 uuid = "6c5e35bf-e59e-4898-b73c-732dcc4ba65f"
 authors = ["ITensor developers <[email protected]> and contributors"]
-version = "0.3.12"
+version = "0.3.14"
 
 [deps]
 Adapt = "79e6a3ab-5dfb-504d-930d-738a2a938a0e"

src/abstractarrayinterface.jl

@@ -5,6 +5,10 @@ function interface(::Type{<:Broadcast.AbstractArrayStyle})
   return DefaultArrayInterface()
 end
 
+function interface(::Type{<:Broadcast.Broadcasted{Nothing}})
+  return DefaultArrayInterface()
+end
+
 function interface(::Type{<:Broadcast.Broadcasted{<:Style}}) where {Style}
   return interface(Style)
 end
@@ -123,9 +127,7 @@ end
 @interface interface::AbstractArrayInterface function Base.copyto!(
   a_dest::AbstractArray, bc::Broadcast.Broadcasted{Broadcast.DefaultArrayStyle{0}}
 )
-  m = Mapped(bc)
-  isempty(m.args) || error("Bad broadcast expression.")
-  return @interface interface map!(m.f, a_dest, a_dest)
+  @interface interface fill!(a_dest, bc.f(bc.args...)[])
 end
 
 # This is defined in this way so we can rely on the Broadcast logic

test/Project.toml

@@ -3,7 +3,6 @@ Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 ArrayLayouts = "4c555306-a7a7-4459-81d9-ec55ddd5c99a"
 DerivableInterfaces = "6c5e35bf-e59e-4898-b73c-732dcc4ba65f"
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"
-MapBroadcast = "ebd9b9da-f48d-417c-9660-449667d60261"
 SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 Suppressor = "fd094767-a336-5f1f-9728-57cf17d0bbfb"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"

test/test_defaultarrayinterface.jl

@@ -33,4 +33,6 @@ end
 
 @testset "Broadcast.DefaultArrayStyle" begin
   @test interface(Broadcast.DefaultArrayStyle) == DefaultArrayInterface()
+  @test interface(Broadcast.Broadcasted(nothing, +, (randn(2), randn(2)))) ==
+    DefaultArrayInterface()
 end