Make collect() and Array() produce Array without categorical value eltype (JuliaData#123)

Author: gustafsson

src/array.jl

@@ -1,6 +1,6 @@
 ## Code for CategoricalArray
 
-import Base: convert, copy, copy!, getindex, setindex!, similar, size,
+import Base: Array, convert, collect, copy, copy!, getindex, setindex!, similar, size,
              unique, vcat, in, summary
 
 # Used for keyword argument default value
@@ -729,6 +729,9 @@ function in(x::CategoricalValue, y::CategoricalArray{T, N, R}) where {T, N, R}
     end
 end
 
+Array(A::CategoricalArray{T}) where {T} = Array{T}(A)
+collect(A::CategoricalArray{T}) where {T} = Array{T}(A)
+
 # Override AbstractArray method to avoid printing useless type parameters
 summary(A::CategoricalArray{T, N, R}) where {T, N, R} =
     string(Base.dims2string(size(A)), " $CategoricalArray{$T,$N,$R}")

test/13_arraycommon.jl

@@ -793,4 +793,32 @@ end
     end
 end
 
+@testset "collect of CategoricalArray produces Array" begin
+    x = [1,1,2,2]
+    y = categorical(x)
+    z = collect(y)
+    @test typeof(x) == typeof(z)
+    @test z == x
+
+    x = [1,1,2,missing]
+    y = categorical(x)
+    z = collect(y)
+    @test typeof(x) == typeof(z)
+    @test z ≅ x
+end
+
+@testset "Array(::CategoricalArray{T}) produces Array{T}" begin
+    x = [1,1,2,2]
+    y = categorical(x)
+    z = Array(y)
+    @test typeof(x) == typeof(z)
+    @test z == x
+
+    x = [1,1,2,missing]
+    y = categorical(x)
+    z = Array(y)
+    @test typeof(x) == typeof(z)
+    @test z ≅ x
+end
+
 end