Specialize scaling by a number

Author: jishnub

src/fillalgebra.jl

@@ -78,6 +78,13 @@ mult_zeros(a::AbstractArray{<:Number}, b::AbstractArray{<:Number}) = mult_zeros(
 mult_zeros(a, b) = mult_fill(a, b, mult_axes(a, b))
 mult_ones(a, b) = mult_ones(a, b, mult_axes(a, b))
 
+# scaling
+*(a::AbstractFill, b::Number) = Fill(getindex_value(a) * b, axes(a))
+*(a::Number, b::AbstractFill) = Fill(a * getindex_value(b), axes(b))
+*(a::AbstractZeros, b::Number) = Zeros(typeof(getindex_value(a) * b), axes(a))
+*(a::Number, b::AbstractZeros) = Zeros(typeof(a * getindex_value(b)), axes(b))
+
+# matmul
 *(a::AbstractFillMatrix, b::AbstractFillMatrix) = mult_fill(a,b)
 *(a::AbstractFillMatrix, b::AbstractFillVector) = mult_fill(a,b)
 

test/runtests.jl

@@ -1167,6 +1167,11 @@ end
 
     @testset "0d" begin
         @test real.(Fill(2)) == real.(fill(2))
+        @test (@. 2 * Fill(2) * 2) == (@. 2 * fill(2) * 2)
+        for (F, A) in ((Fill(2), fill(2)), (Zeros(), zeros()), (Ones(), ones()))
+            @test F * 2 == A * 2
+            @test 2 * F == 2 * A
+        end
     end
 
     @testset "preserve 0d" begin