Add broadcasting

Author: lkdvos

src/SparseArraysBase.jl

@@ -19,7 +19,7 @@ using DerivableInterfaces
 include("abstractsparsearrayinterface.jl")
 include("indexing.jl")
 include("map.jl")
-include("sparsearrayinterface.jl")
+include("broadcast.jl")
 
 # types
 include("wrappers.jl")

src/broadcast.jl

@@ -0,0 +1,31 @@
+using Base.Broadcast: Broadcasted
+using MapBroadcast: Mapped
+
+abstract type AbstractSparseArrayStyle{N} <: Broadcast.AbstractArrayStyle{N} end
+
+struct SparseArrayStyle{N} <: AbstractSparseArrayStyle{N} end
+SparseArrayStyle{M}(::Val{N}) where {M,N} = SparseArrayStyle{N}()
+
+DerivableInterfaces.interface(::Type{<:AbstractSparseArrayStyle}) = SparseArrayInterface()
+
+@derive (T=AbstractSparseArrayStyle,) begin
+  Base.similar(::Broadcasted{<:T}, ::Type, ::Tuple)
+  Base.copyto!(::AbstractArray, ::Broadcasted{<:T})
+end
+
+@interface ::AbstractSparseArrayInterface function Broadcast.BroadcastStyle(type::Type)
+  return SparseArrayStyle{ndims(type)}()
+end
+
+@interface I::AbstractSparseArrayInterface function Base.similar(
+  ::Broadcasted, ::Type{T}, ax
+) where {T}
+  return similar(I, T, ax)
+end
+
+@interface I::AbstractSparseArrayInterface function Base.copyto!(
+  C::AbstractArray, bc::Broadcasted
+)
+  m = Mapped(bc)
+  return @interface I map!(m.f, C, m.args...)
+end