Add #[darling(word)] for enum variants

[TedDriggs]

DefaultExpression is one example of an enum that wants to map a specific variant to the appearance of the field ident with no associated value. This would only be valid on variants in FromMeta. The variant must be a unit variant.

[TedDriggs]

@chipsenkbeil I think this is what you're looking for ent(field)

[chipsenkbeil]

In my case, I'm looking for a word or a list as the attribute can be #[ent(field)] if just marking a struct field as an entity field, or something like #[ent(field(indexed, mutable))] if marking as an entity field with special flags.

Separately, I also have #[ent(edge)] that can have #[ent(edge(type = "some::type", policy = "SomeEnumVariant"))].

To summarize, I'm both looking for the presence of field or edge as a boolean indicator as well as optional inner words/named values to assign other properties. All of the inner content comes across as optional, with words defaulting to false as booleans and types defaulting to None/a default value.

[TedDriggs]

Check out darling::util::Override. The naming isn't the most obvious for your use-case, but I believe it does what you're looking for if you use Option<Override<EdgeOpts>>.

[TedDriggs]

Given the existence of the above workaround (and the lack of movement for almost 3 years), I'm closing this as "Won't Fix."