Allow symbol/string literal types

[lekemula]

Hi,

Coming from the solargraph-rspec Ruby LSP plugin side here, sometimes it is useful to declare enum-like possible literals: @param [:some_symbol, :some_other_symbol].

While this is not part of the YARD https://www.rubydoc.info/gems/yard/file/docs/Tags.md#literals specification, as the YARD author mentions, that list is non-exhaustive, leaving room for such cases.

Would it make sense to extend YARD/TagTypeSyntax to allow :symbol and 'string' literals, or at least add a configuration flag to permit them?

If you find this acceptable, I can also look into extending/adding it myself.

[ksss]

Same as #33 .

In YARD/TagTypeSyntax Cop, “Tag type syntax” is defined as “Whether it can be parsed by YARD::Tags::TypesExplainer::Parser.parse(type).”
I don’t know why this method doesn’t support String or Symbol literals.
Meanwhile, some implementations do support literals.

https://github.com/lsegal/yardoc.org/blob/62841134db091994fab292978c885dcf87af6863/public/js/types.js#L12

Here are the directions I can propose:

1. Add literal types to YARD itself
2. Extend the specification of “Tag type syntax” in this repository
3. Consider it outside the scope of YARD/TagTypeSyntax and ignore the Cop

If the proposal in this issue is (2), then we’ll need a simple specification and a parser (probably a regular expression).

[lekemula]

Sorry for missing the other issue.

The 1) and 2) suggestions make sense - I've opened an issue upstream lsegal/yard#1627.

Being that yardoc.org/types.html does seem to parse it properly, I have high hopes that we'll get to fix it there 🤞.

Thanks for your response.

[lekemula]

Also opened a PR there: lsegal/yard#1628