Distinguishing between different null types #143
Description
Currently, these is only one type of null in the code generator. The following code
json = """
[
{"a": null, "b": 1},
{"a": null, "b": null}
]
"""
JSON3.generate_exprs(JSON3.generate_type(JSON3.read(json)), mutable=false)produces this struct
struct Root
a::Nothing
b::Union{Nothing, Int64}
endThis is only because the field a does not have enough samples to produce a meaningful type. On the other hand, the values in b are typical in JSON and would be nice to represent with "the software engineer's null" (JuliaLang/julia#22682). I would like the code generator to output something like
const Maybe{T} = Union{Some{T}, Nothing}
struct Root
a::Missing
b::Maybe{Int64}
endor
const Maybe{T} = Union{Some{T}, Nothing}
struct Root
a::Any
b::Maybe{Int64}
end