julia> Meta.parse(repr(categorical(["placebo"])[1]))
ERROR: ParseError:
# Error @ none:1:33
CategoricalValue{String, UInt32} "placebo"
#                               └────────┘ ── extra tokens after end of expression
Stacktrace:
 [1] #parse#3
   @ ./meta.jl:242 [inlined]
 [2] parse
   @ ./meta.jl:234 [inlined]
 [3] parse(str::String; filename::String, raise::Bool, depwarn::Bool)
   @ Base.Meta ./meta.jl:276
 [4] parse(str::String)
   @ Base.Meta ./meta.jl:274
 [5] top-level scope
   @ REPL[151]:1

julia> [String7("placebo")]
1-element Vector{String7}:
 "placebo"

julia> categorical([String7("placebo")])
1-element CategoricalArray{String7,1,UInt32}:
 String7("placebo")