Method prepare

crates/vm/src/anystr.rs:58–73

(self, s: &S, len: usize, substr: F)

    #[inline]
    pub fn prepare<S, F>(self, s: &S, len: usize, substr: F) -> Option<(PyObjectRef, &S)>
    where
        S: ?Sized + AnyStr,
        F: Fn(&S, Range<usize>) -> &S,
    {
        let (affix, range) = self.get_value(len);
        let substr = if let Some(range) = range {
            if !range.is_normal() {
                return None;
            }
            substr(s, range)
        } else {
            s
        };
        Some((affix, substr))
    }
}

fn saturate_to_isize(py_int: PyIntRef) -> isize {