ScientificTypes.scitype(Any[]) errors (but other empty vectors work fine)

[DilumAluthge]

julia> ScientificTypes.scitype(Any[])
ERROR: ArgumentError: reducing over an empty collection is not allowed
Stacktrace:
  [1] _empty_reduce_error()
    @ Base ./reduce.jl:299
  [2] mapreduce_empty(f::Function, op::Base.BottomRF{ScientificTypes.var"#8#9"}, T::Type)
    @ Base ./reduce.jl:342
  [3] reduce_empty(op::Base.MappingRF{typeof(ScientificTypes.scitype),Base.BottomRF{ScientificTypes.var"#8#9"}}, #unused#::Type{Any})
    @ Base ./reduce.jl:329
  [4] reduce_empty_iter(op::Base.MappingRF{typeof(ScientificTypes.scitype),Base.BottomRF{ScientificTypes.var"#8#9"}}, itr::Vector{Any}, #unused#::Base.HasEltype)
    @ Base ./reduce.jl:355
  [5] reduce_empty_iter(op::Base.MappingRF{typeof(ScientificTypes.scitype),Base.BottomRF{ScientificTypes.var"#8#9"}}, itr::Vector{Any})
    @ Base ./reduce.jl:354
  [6] foldl_impl
    @ ./reduce.jl:49 [inlined]
  [7] mapfoldl_impl
    @ ./reduce.jl:44 [inlined]
  [8] #mapfoldl#196
    @ ./reduce.jl:160 [inlined]
  [9] mapfoldl
    @ ./reduce.jl:160 [inlined]
 [10] #mapreduce#200
    @ ./reduce.jl:287 [inlined]
 [11] mapreduce
    @ ./reduce.jl:287 [inlined]
 [12] #reduce#202
    @ ./reduce.jl:456 [inlined]
 [13] reduce
    @ ./reduce.jl:456 [inlined]
 [14] scitype_union
    @ ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:26 [inlined]
 [15] #arr_scitype#11
    @ ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:92 [inlined]
 [16] arr_scitype
    @ ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:92 [inlined]
 [17] #scitype#10
    @ ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:77 [inlined]
 [18] scitype(A::Vector{Any}, C::MLJScientificTypes.MLJ, ::Val{:other})
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:77
 [19] scitype(X::Vector{Any}, C::MLJScientificTypes.MLJ; kw::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}})
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:10
 [20] scitype(X::Vector{Any}, C::MLJScientificTypes.MLJ)
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:10
 [21] scitype(X::Vector{Any}; kw::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}})
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:9
 [22] scitype(X::Vector{Any})
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:9
 [23] top-level scope
    @ REPL[9]:1

Steps to reproduce:

In Bash:

rm -rf ~/.julia

In Julia:

julia> import Pkg

julia> Pkg.add(["ScientificTypes", "MLJScientificTypes"])

julia> import ScientificTypes
[ Info: Precompiling ScientificTypes [321657f4-b219-11e9-178b-2701a2544e81]

julia> import MLJScientificTypes
[ Info: Precompiling MLJScientificTypes [2e2323e0-db8b-457b-ae0d-bdfb3bc63afd]

julia> ScientificTypes.set_convention(MLJScientificTypes.MLJ())

julia> ScientificTypes.scitype(Int[])
AbstractVector{ScientificTypes.Count} = AbstractArray{ScientificTypes.Count,1}

julia> ScientificTypes.scitype(Float64[])
AbstractVector{ScientificTypes.Continuous} = AbstractArray{ScientificTypes.Continuous,1}

julia> ScientificTypes.scitype(String[])
AbstractVector{ScientificTypes.Textual} = AbstractArray{ScientificTypes.Textual,1}

julia> ScientificTypes.scitype(Any[])
ERROR: ArgumentError: reducing over an empty collection is not allowed
Stacktrace:
  [1] _empty_reduce_error()
    @ Base ./reduce.jl:299
  [2] mapreduce_empty(f::Function, op::Base.BottomRF{ScientificTypes.var"#8#9"}, T::Type)
    @ Base ./reduce.jl:342
  [3] reduce_empty(op::Base.MappingRF{typeof(ScientificTypes.scitype),Base.BottomRF{ScientificTypes.var"#8#9"}}, #unused#::Type{Any})
    @ Base ./reduce.jl:329
  [4] reduce_empty_iter(op::Base.MappingRF{typeof(ScientificTypes.scitype),Base.BottomRF{ScientificTypes.var"#8#9"}}, itr::Vector{Any}, #unused#::Base.HasEltype)
    @ Base ./reduce.jl:355
  [5] reduce_empty_iter(op::Base.MappingRF{typeof(ScientificTypes.scitype),Base.BottomRF{ScientificTypes.var"#8#9"}}, itr::Vector{Any})
    @ Base ./reduce.jl:354
  [6] foldl_impl
    @ ./reduce.jl:49 [inlined]
  [7] mapfoldl_impl
    @ ./reduce.jl:44 [inlined]
  [8] #mapfoldl#196
    @ ./reduce.jl:160 [inlined]
  [9] mapfoldl
    @ ./reduce.jl:160 [inlined]
 [10] #mapreduce#200
    @ ./reduce.jl:287 [inlined]
 [11] mapreduce
    @ ./reduce.jl:287 [inlined]
 [12] #reduce#202
    @ ./reduce.jl:456 [inlined]
 [13] reduce
    @ ./reduce.jl:456 [inlined]
 [14] scitype_union
    @ ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:26 [inlined]
 [15] #arr_scitype#11
    @ ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:92 [inlined]
 [16] arr_scitype
    @ ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:92 [inlined]
 [17] #scitype#10
    @ ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:77 [inlined]
 [18] scitype(A::Vector{Any}, C::MLJScientificTypes.MLJ, ::Val{:other})
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:77
 [19] scitype(X::Vector{Any}, C::MLJScientificTypes.MLJ; kw::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}})
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:10
 [20] scitype(X::Vector{Any}, C::MLJScientificTypes.MLJ)
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:10
 [21] scitype(X::Vector{Any}; kw::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}})
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:9
 [22] scitype(X::Vector{Any})
    @ ScientificTypes ~/.julia/packages/ScientificTypes/b8I2Y/src/scitype.jl:9
 [23] top-level scope
    @ REPL[9]:1

To edit a specific method, type the corresponding number into the REPL and press Ctrl+Q

julia> Pkg.status()
Status `~/.julia/environments/v1.6/Project.toml`
  [2e2323e0] MLJScientificTypes v0.2.8
  [321657f4] ScientificTypes v0.8.0

julia> import InteractiveUtils

julia> InteractiveUtils.versioninfo()
Julia Version 1.6.0-DEV.569
Commit 84ef118f06 (2020-08-01 18:56 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin19.6.0)
  CPU: Intel(R) Core(TM) i5-4278U CPU @ 2.60GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-9.0.1 (ORCJIT, haswell)

[tlienart]

I'll have a look, thanks for the heads up :)