Configurations.jl Read Vector of Multiple Possible Types from TOML File

General Usage
1

Say that I have two custom option types, TypeA and TypeB defined below:

using Configurations

@option "type_a" struct TypeA
    type::Reflect
    a::Int
end

@option "type_b" struct TypeB
    type::Reflect
    b::Int
end

And I also have an option type that holds a vector of type Union{TypeA, TypeB}:

@option struct VectorType
    vec::Vector{Union{TypeA,TypeB}}
end

I’m am currently able to create a .toml file using this type as follows:

test_vec = VectorType([TypeA(Reflect(), 1), TypeB(Reflect(), 2)])
to_toml(joinpath(@__DIR__, "test.toml"), test_vec)

which creates test.toml as:

[[vec]]
type = "type_a"
a = 1

[[vec]]
type = "type_b"
b = 2

However I am unable to read the .toml back into my custom type:

test_vec = from_toml(VectorType, joinpath(@__DIR__, "test.toml"))

ERROR: ArgumentError: cannot parse type_a to a Julia type
Stacktrace:
  [1] parse_jltype(s::String, alias_map::Nothing)
    @ Configurations ~/.julia/packages/Configurations/Yxczn/src/utils.jl:46
  [2] macro expansion
    @ ~/.julia/packages/Configurations/Yxczn/src/from_dict.jl:430 [inlined]
  [3] from_dict_union_type(#unused#::Type{VectorType}, #unused#::OptionField{:vec}, #unused#::Type{Union{TypeA, TypeB}}, value::Dict{String, Any})
    @ Configurations ~/.julia/packages/Configurations/Yxczn/src/from_dict.jl:170
  [4] (::Configurations.var"#7#9"{VectorType, Vector{Union{TypeA, TypeB}}, OptionField{:vec}})(each::Dict{String, Any})
    @ Configurations ~/.julia/packages/Configurations/Yxczn/src/from_dict.jl:133
  [5] iterate
    @ ./generator.jl:47 [inlined]

Is this possible in the Configuration.jl package. Any help is appreciated.

Thanks!

@Roger-luo

2

Err that looks like a bug lol. The Unions are not handled very well in the current implementation. I’ve created an issue but I prob won’t have much time fixing this for now.

3

Okay thanks for letting me know, I appreciate it.