Re: [PATCH v3] rust: introduce sfile macro for succinct code tracing

["Benno Lossin" <lossin@kernel.org>]

On Tue Jun 10, 2025 at 5:40 AM CEST, Timur Tabi wrote:
> On Mon, 2025-06-09 at 19:33 -0700, John Hubbard wrote:
>> > +/// Returns the index of the last occurrence of `needle` in `haystack`, or zero.
>> > +///
>> > +/// Identical to [`str::rfind()`], but unlike that function, this one is const.
>> > +/// That is, the compiler can inline it when called with a string literal.
>> > +#[inline]
>> > +pub const fn rfind_const(haystack: &str, needle: char) -> Option<usize> {
>> > +    let bytes = haystack.as_bytes();
>> 
>> Silly nit: "bytes" is just adding an unnecessary variable that also has
>> a non-informative name. Just delete it...
>> 
>> > +    let mut i = haystack.len();
>> > +    while i > 0 {
>> > +        i -= 1;
>> > +        if bytes[i] == needle as u8 {
>> 
>> ...and write the above line accordingly:
>> 
>> 	if haystack.as_bytes()[i] == needle as u8 {
>> 
>> 
>> Yes?
>
> I find my version to be easier to read.  I like using temporary local variables to keep my code
> cleaner.
>
> If I post a v4, I can try to come up with a better name.

You can just reuse haystack:

    let haystack = haystack.as_bytes();

---
Cheers,
Benno