import JSON fails with utf16_is_surrogate undefined

[rajathshashidhara]

Fails at Line 141 in Parser.jl
on using JSON

[swt30]

Introduced by JuliaLang/julia#11551, specifically JuliaLang/julia@a286ce0 which appears to have removed utf16_is_surrogate. In at least one place it's replaced by is_surrogate_codeunit (JuliaLang/julia@a286ce0#diff-c77c77957abcbf5ff43edad984ad701dR48)

[IainNZ]

@ScottPJones your expertise needed here

[ScottPJones]

I'm adding something to deprecate.
The problem is that the JSON package is using an undocumented, unexported function,
and when I first wrote the UTF checking/conversion code, I wasn't aware that that was being done
(I now have all of the registered packages downloaded, and grep to make sure anything I change is tested/deprecated if it is used anywhere in the packages).

[IainNZ]

Best solution might be to fix JSON.jl to use only documented functions, if at all possible, rather than adding a deprecation to Base.

[IainNZ]

Normally PkgEval could identify all the breakages but the one thing it needs to work is JSON

[ScottPJones]

Should I just submit a PR to the JSON package instead?

[IainNZ]

Ideally yes. Although, it seems like here:
https://github.com/JuliaLang/JSON.jl/blob/e583641c540dcdafbbe4f748cd12cba544ce12c5/src/Parser.jl#L137-L143
It might sufficient just to back to the pre-0.3.0 definitions? Ideally though we'd use the code from Base though in some sensible way. We can drop the pre-0.3 stuff too.

[ScottPJones]

They should use their own, at least until functions that are made to be public are placed in Base.

[ScottPJones]

Fixed in #111