Fix type instability of norm(::AbstractFill, p::Int) (#418)

Fixes #417.

Author: mtfishman

Project.toml

@@ -1,6 +1,6 @@
 name = "FillArrays"
 uuid = "1a297f60-69ca-5386-bcde-b61e274b549b"
-version = "1.14.0"
+version = "1.14.1"
 
 [deps]
 LinearAlgebra = "37e2e46d-f89d-539d-b4ee-838fcccc9c8e"

src/fillalgebra.jl

@@ -496,8 +496,14 @@ end
 normp(a::AbstractZeros, p) = norm(getindex_value(a))
 
 norm1(a::AbstractFill) = length(a)*norm(getindex_value(a))
-norm2(a::AbstractFill) = sqrt(length(a))*norm(getindex_value(a))
-normp(a::AbstractFill, p) = (length(a))^(1/p)*norm(getindex_value(a))
+function norm2(a::AbstractFill)
+    nrm1 = norm(getindex_value(a))
+    sqrt(oftype(nrm1, length(a)))*nrm1
+end
+function normp(a::AbstractFill, p)
+    nrm1 = norm(getindex_value(a))
+    (length(a))^(1/oftype(nrm1, p))*nrm1
+end
 normInf(a::AbstractFill) = norm(getindex_value(a))
 normMinusInf(a::AbstractFill) = norm(getindex_value(a))
 

test/runtests.jl

@@ -1888,11 +1888,12 @@ end
 end
 
 @testset "norm" begin
-    for a in (Zeros{Int}(5), Zeros(5,3), Zeros(2,3,3),
-                Ones{Int}(5), Ones(5,3), Ones(2,3,3),
-                Fill(2.3,5), Fill([2.3,4.2],5), Fill(4)),
+    for a in (Zeros{Int}(5), Zeros(5,3), Zeros(2,3,3), Zeros{ComplexF32}(5),
+                Ones{Int}(5), Ones(5,3), Ones(2,3,3), Ones{ComplexF32}(5),
+                Fill(2.3,5), Fill([2.3,4.2],5), Fill(4), Fill(2f0+3f0im,5)),
         p in (-Inf, 0, 0.1, 1, 2, 3, Inf)
-        @test norm(a,p) ≈ norm(Array(a),p)
+        @test @inferred(norm(a,p)) ≈ norm(Array(a),p)
+        @test typeof(norm(a,p)) == typeof(norm(Array(a),p))
     end
 end