Merge pull request #65 from JuliaGaussianProcesses/nothing-flatten

Add support for `nothing`

Author: simsurace

Project.toml

@@ -1,7 +1,7 @@
 name = "ParameterHandling"
 uuid = "2412ca09-6db7-441c-8e3a-88d5709968c5"
 authors = ["Invenia Technical Computing Corporation"]
-version = "0.4.7"
+version = "0.4.8"
 
 [deps]
 ChainRulesCore = "d360d2e6-b24c-11e9-a2a3-2a2ae2dbcce4"

src/flatten.jl

@@ -19,9 +19,15 @@ function flatten end
 
 flatten(x) = flatten(Float64, x)
 
+function flatten(::Type{T}, ::Nothing) where {T<:Real}
+    v = T[]
+    unflatten_to_Nothing(::Vector{T}) = nothing
+    return v, unflatten_to_Nothing
+end
+
 function flatten(::Type{T}, x::Integer) where {T<:Real}
     v = T[]
-    unflatten_to_Integer(v::Vector{T}) = x
+    unflatten_to_Integer(::Vector{T}) = x
     return v, unflatten_to_Integer
 end
 

test/flatten.jl

@@ -8,6 +8,11 @@
         end
     end
 
+    @testset "Nothing" begin
+        test_flatten_interface(nothing)
+        @test isempty(first(flatten(nothing)))
+    end
+
     @testset "AbstractArrays" begin
         test_flatten_interface(randn(10))
         test_flatten_interface(randn(5, 4))