Function find_options_with_keywords

crates/csskit_proc_macro/src/generate.rs:332–356

Find Options combinators containing keyword (Ident) children that need helper structs. Searches: direct Alternatives children, and NoneOr/AutoOr/NormalOr/AutoNoneOr wrappers.

(def: &Def)

/// Find Options combinators containing keyword (Ident) children that need helper structs.
/// Searches: direct Alternatives children, and NoneOr/AutoOr/NormalOr/AutoNoneOr wrappers.
fn find_options_with_keywords(def: &Def) -> Vec<&Def> {
	fn is_options_with_keywords(def: &Def) -> bool {
		if let Def::Combinator(defs, DefCombinatorStyle::Options) = def {
			defs.iter().any(|d| !matches!(d, Def::Type(_) | Def::StyleValue(_)))
		} else {
			false
		}
	}
	fn unwrap_to_options(def: &Def) -> Option<&Def> {
		match def {
			Def::Group(inner, _) => unwrap_to_options(inner),
			d if is_options_with_keywords(d) => Some(d),
			_ => None,
		}
	}
	match def {
		Def::Combinator(children, DefCombinatorStyle::Alternatives) => {
			children.iter().filter_map(unwrap_to_options).collect()
		}
		Def::NoneOr(inner) | Def::AutoOr(inner) | Def::NormalOr(inner) | Def::AutoNoneOr(inner) => {
			unwrap_to_options(inner).into_iter().collect()
		}
		_ => vec![],
	}
}

/// For a list of sibling `Combinator(Options, ...)` children, compute each child's
/// distinguishing keyword set: the keywords that appear in this child but NOT in some other