Function classify

crates/rust/src/lib.rs:1973–2005

(
        resolve: &Resolve,
        resource_id: TypeId,
        result: &Option<Type>,
    )

    result: &Option<Type>,
) -> ConstructorReturnType {
    fn classify(
        resolve: &Resolve,
        resource_id: TypeId,
        result: &Option<Type>,
    ) -> Option<ConstructorReturnType> {
        let resource_id = dealias(resolve, resource_id);
        let typedef = match result.as_ref()? {
            Type::Id(id) => &resolve.types[dealias(resolve, *id)],
            _ => return None,
        };

        match &typedef.kind {
            TypeDefKind::Handle(Handle::Own(id)) if dealias(resolve, *id) == resource_id => {
                Some(ConstructorReturnType::Self_)
            }
            TypeDefKind::Result(Result_ { ok, err }) => {
                let ok_typedef = match ok.as_ref()? {
                    Type::Id(id) => &resolve.types[dealias(resolve, *id)],
                    _ => return None,
                };

                match &ok_typedef.kind {
                    TypeDefKind::Handle(Handle::Own(id))
                        if dealias(resolve, *id) == resource_id =>
                    {
                        Some(ConstructorReturnType::Result { err: *err })
                    }
                    _ => None,
                }
            }
            _ => None,
        }
    }

    classify(resolve, resource_id, result).expect("invalid constructor")
}