MethodError: isvalid(::String31)

[jariji]

This method would be useful:

ERROR: MethodError: no method matching isvalid(::String31)

[nickrobinson251]

i wonder if the correct definition is just the same as for String
https://github.com/JuliaLang/julia/blob/cdcb07f13c10611f3a2fe4d491a8d0342ad11d12/base/strings/string.jl#L194-L201

(here's the u8_isvalid definition: https://github.com/JuliaLang/julia/blob/cdcb07f13c10611f3a2fe4d491a8d0342ad11d12/src/support/utf8.c#L542-L596)

i.e. something like

Base.isvalid(s::InlineString) = ccall(:u8_isvalid, Int32, (Ptr{UInt8}, Int), s, sizeof(s)) != 0

i think the only thing this doesn't do is check the last byte (the length of the InlineString) in any way -- do we need to check that?

[quinnj]

Nah, we don't need to check the length; yeah, that definition sounds good to me. @jariji, mind making a PR with a test?

[stevengj]

With JuliaLang/julia#47880 (which should be in Julia 1.10), you shouldn't need to do anything — it adds a fallback method isvalid(s::AbstractString) = @inline isvalid(String, codeunits(s)), which in turn calls isvalid(::Type{String}, bytes::AbstractVector{UInt8}). So it should just work for InlineString.

[KristofferC]

I think it is fine to close this with the feature being included into 1.10 which will soon be the new LTS: