Re: [PATCH v2 03/11] rust: macros: convert `#[vtable]` macro to use `syn`

[Gary Guo <gary@garyguo.net>]

On Thu, 8 Jan 2026 10:10:23 -0500
Tamir Duberstein <tamird@gmail.com> wrote:

> > > > +    let mut consts = HashSet::new();
> > > > +    for name in functions {
> > > > +        let gen_const_name = Ident::new(
> > > > +            &format!("HAS_{}", name.to_string().to_uppercase()),
> > > > +            name.span(),
> > > > +        );
> > > > +        // Skip if it's declared already -- this can happen if `#[cfg]` is used to selectively
> > > > +        // define functions.
> > > > +        // FIXME: `#[cfg]` should be copied and propagated to the generated consts.
> > > > +        if consts.contains(&gen_const_name) {
> > > > +            continue;
> > > > +        }
> > > > +        // We don't know on the implementation-site whether a method is required or provided
> > > > +        // so we have to generate a const for all methods.
> > > > +        let comment = format!("Indicates if the `{name}` method is overridden by the implementor.");  
> > >
> > > We're already quasi-quoting below, does putting the comment there work?  
> >
> > The comment has `{name}` interpolation and you cannot just use `quote!`
> > for it.
> >
> > You could do
> >
> >         #[doc = concat!("...", stringify!(...), "...")]
> >
> > But I think it's cleaner to just use `format!`.  
> 
> Ack, though I think it would be:
> 
> #[doc = concat!("Indicates if the `", #name, "` method is overridden
> by the implementor.")]
> 
> i.e. no need for `stringify`.

Note `name` here is an `Ident`, which gets turned into an identifer, not a
string, so if `concat!` is used stringify is still necessary.

Anyway, I'm going to keep `format!` in the new version.

Best,
Gary