WeakRefStringArray: make eltype respect Missing

enhances #17 so that WeakRefStringArray allows missing iff the underlying WeakRefString Array allows missing
JuliaData · Dec 20, 2017 · 45d595d · 45d595d
1 parent 744f4eb
commit 45d595d
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Showing 2 changed files with 18 additions and 6 deletions.
diff --git a/src/WeakRefStrings.jl b/src/WeakRefStrings.jl
@@ -75,15 +75,18 @@ Base.convert(::Type{String}, x::WeakRefString) = convert(String, string(x))
 Base.String(x::WeakRefString) = string(x)
 Base.Symbol(x::WeakRefString{UInt8}) = ccall(:jl_symbol_n, Ref{Symbol}, (Ptr{UInt8}, Int), x.ptr, x.len)
 
-struct WeakRefStringArray{T, N} <: AbstractArray{Union{String, Missing}, N}
+struct WeakRefStringArray{T, N, U} <: AbstractArray{Union{String, U}, N}
     data::Vector{Any}
-    elements::Array{T, N}
+    elements::Array{Union{T, U}, N}
+
+    WeakRefStringArray(data::Vector{UInt8}, ::Type{T}, rows::Integer) where {T <: WeakRefString} =
+        new{T, 1, Union{}}(Any[data], zeros(T, rows))
+    WeakRefStringArray(data::Vector{UInt8}, ::Type{Union{T, Missing}}, rows::Integer) where {T <: WeakRefString} =
+        new{T, 1, Missing}(Any[data], Vector{Union{T, Missing}}(rows))
+    WeakRefStringArray(data::Vector{UInt8}, A::Array{T, N}) where {T <: Union{WeakRefString, Missing}, N} =
+        new{Missings.T(T), N, T >: Missing ? Missing : Union{}}(Any[data], A)
 end
 
-WeakRefStringArray(data::Vector{UInt8}, ::Type{T}, rows::Integer) where {T <: WeakRefString} = WeakRefStringArray(Any[data], zeros(T, rows))
-WeakRefStringArray(data::Vector{UInt8}, ::Type{Union{Missing, T}}, rows::Integer) where {T} = WeakRefStringArray(Any[data], Vector{Union{Missing, T}}(rows))
-WeakRefStringArray(data::Vector{UInt8}, A::Array{T}) where {T <: Union{WeakRefString, Missing}} = WeakRefStringArray(Any[data], A)
-
 wk(w::WeakRefString) = string(w)
 wk(::Missing) = missing
 

diff --git a/test/runtests.jl b/test/runtests.jl
@@ -51,6 +51,7 @@ end
     str = WeakRefString(pointer(data), 3)
     C = WeakRefStringArray(data, [str])
     @test size(C) == (1,)
+    @test eltype(C) === String
 
     A = WeakRefStringArray(UInt8[], WeakRefString{UInt8}, 10)
     @test size(A) == (10,)
@@ -72,6 +73,8 @@ end
     B[1] = "ho"
     append!(A, B)
     @test size(A) == (17,)
+    @test_throws MethodError setindex!(B, missing, 1)
+    @test_throws MethodError push!(B, missing)
 
     D = WeakRefStringArray(UInt8[], Union{Missing, WeakRefString{UInt8}}, 0)
     push!(D, "hey")
@@ -82,4 +85,10 @@ end
     @test D[3] === missing
     D[2] = missing
     @test D[2] === missing
+    @test_throws MethodError append!(A, D)
+    @test_broken size(A) == (17,) # append!() changes the size of A
+
+    E = WeakRefStringArray(data, [str missing])
+    @test size(E) == (1, 2)
+    @test eltype(E) === Union{String, Missing}
 end