Conversion example inconsistent with conversion description

[Azquelt]

Describe the bug

The Config Value Conversion Rules section of the spec includes this:

Value	Convert To	Method	Result
"\,"	String	getValue	"\,"
"\,"	String[]	getValue	throws NoSuchElementException
"\,"	String	getOptionalValue	Optional.of("\,")
"\,"	String[]	getOptionalValue	Optional.empty()
"\,"	String	getOptionalValues	Optional.empty()

I think this is wrong. Since \ is used as an escape character, the list style conversions should treat the , as a literal character, rather than a separator, so the result for getValue with String[] would be {","}.

I'm unsure whether this table should also have code tags around almost every entry. (My only doubt here is that \ is also the string escape in Java, so it could be confusing as to whether we're using Java's string syntax or not if it's formatted as code)

[Azquelt]

I note that this case was listed as 3(b) in #446, and I'm not looking to reopen that discussion, but it does seem like the example in the spec contradicts the description of the rules here and here.

When I read the example, I assumed it was just a copy-paste error, but I'm happy for the other parts of the spec to change if the example is correct.

[Azquelt]

Smallrye Config has a specific check to not add a value of , to the array as the last step of converting the value: https://github.com/smallrye/smallrye-config/blob/7258a167a3f3ab26839749a37485bdf0edf749fe/implementation/src/main/java/io/smallrye/config/Converters.java#L718

I.e. "\," is converted to a single element "," which is then ignored because it's a single comma.

[Emily-Jiang]

@Azquelt in this table you quoted, can you point out which row is wrong. Do you just say \, 4b is inconsistent or any row in the table you quoted is wrong?

[Azquelt]

Sorry, I just realised that github's formatting had removed my backslashes, making it make no sense. I've now corrected it.

I think that rows 2, 4 and 5 of the part of the table that I quoted are wrong.

They should be

Value	Convert To	Method	Result
"\,"	String[]	getValue	{","}
"\,"	String[]	getOptionalValue	Optional.of({","})
"\,"	String	getOptionalValues	Optional.of(List.of(","))

[Emily-Jiang]

The suggestion from @Azquelt sounds reasonable to me, since \ is an escape character for array of strings. @radcortez @jbee thoughts?

[jbee]

Sounds reasonable to me.

[radcortez]

Ok.

[Emily-Jiang]

Thanks @radcortez @jbee! Let me propose a PR to get it fixed.