[PATCH v2 2/5] rust: macros: extend custom `quote!()` macro

[Alice Ryhl]

On Fri, Aug 15, 2025 at 7:32 AM Jesung Yang <y.j3ms.n at gmail.com> wrote:
>
> Extend the `quote_spanned!()` macro to support additional punctuation
> tokens: `->`, `<`, `>`, and `==`. This symbols are commonly needed when
> dealing with functions, generic bounds, and equality comparisons.
>
> Tested-by: Alexandre Courbot <acourbot at nvidia.com>
> Signed-off-by: Jesung Yang <y.j3ms.n at gmail.com>
> ---
>  rust/macros/quote.rs | 30 ++++++++++++++++++++++++++++++
>  1 file changed, 30 insertions(+)
>
> diff --git a/rust/macros/quote.rs b/rust/macros/quote.rs
> index 8a89f0b1e785..24764b04a07d 100644
> --- a/rust/macros/quote.rs
> +++ b/rust/macros/quote.rs
> @@ -150,6 +150,36 @@ macro_rules! quote_spanned {
>          ));
>          quote_spanned!(@proc $v $span $($tt)*);
>      };
> +    (@proc $v:ident $span:ident -> $($tt:tt)*) => {
> +        $v.push(::proc_macro::TokenTree::Punct(
> +                ::proc_macro::Punct::new('-', ::proc_macro::Spacing::Joint)
> +        ));
> +        $v.push(::proc_macro::TokenTree::Punct(
> +                ::proc_macro::Punct::new('>', ::proc_macro::Spacing::Alone)
> +        ));
> +        quote_spanned!(@proc $v $span $($tt)*);
> +    };
> +    (@proc $v:ident $span:ident < $($tt:tt)*) => {
> +        $v.push(::proc_macro::TokenTree::Punct(
> +                ::proc_macro::Punct::new('<', ::proc_macro::Spacing::Alone)
> +        ));
> +        quote_spanned!(@proc $v $span $($tt)*);
> +    };
> +    (@proc $v:ident $span:ident > $($tt:tt)*) => {
> +        $v.push(::proc_macro::TokenTree::Punct(
> +                ::proc_macro::Punct::new('>', ::proc_macro::Spacing::Alone)
> +        ));
> +        quote_spanned!(@proc $v $span $($tt)*);
> +    };
> +    (@proc $v:ident $span:ident == $($tt:tt)*) => {
> +        $v.push(::proc_macro::TokenTree::Punct(
> +                ::proc_macro::Punct::new('=', ::proc_macro::Spacing::Joint)
> +        ));
> +        $v.push(::proc_macro::TokenTree::Punct(
> +                ::proc_macro::Punct::new('=', ::proc_macro::Spacing::Alone)
> +        ));
> +        quote_spanned!(@proc $v $span $($tt)*);

Not a blocker, but if the way to implement this one is to push =
twice, then I think the pattern should just be a single = and then you
push a = once. The pattern can match twice to handle ==.

Alice