pub trait VecDot: num_traits::NumAssign + Copy {
    /// Dot-product of two vectors.
    ///
    /// # Safety
    ///
    /// The length of `lhs` and `rhs` have to be at least `len`. `res` has to point to a valid
    /// element.
    #[inline(always)]
    unsafe fn vec_dot(lhs: *const Self, rhs: *const Self, res: *mut Self, len: usize) {
        *res = Self::zero();
        for i in 0..len {
            *res += *lhs.add(i) * *rhs.add(i)
        }
    }
}

impl VecDot for f32 {
    #[inline(always)]
    unsafe fn vec_dot(lhs: *const Self, rhs: *const Self, res: *mut Self, len: usize) {
        ggblas::ggml::vec_dot_f32(lhs, rhs, res, len)
    }
}

impl VecDot for f64 {}
impl VecDot for half::bf16 {}
impl VecDot for half::f16 {}
impl VecDot for u8 {}
impl VecDot for u32 {}

#[inline(always)]
pub fn par_for_each(n_threads: usize, func: impl Fn(usize) + Send + Sync) {
    if n_threads == 1 {
        func(0)
    } else {
        rayon::scope(|s| {
            for thread_idx in 0..n_threads {
                let func = &func;
                s.spawn(move |_| func(thread_idx));
            }
        })
    }
}

#[inline(always)]
pub fn par_range(lo: usize, up: usize, n_threads: usize, func: impl Fn(usize) + Send + Sync) {
    if n_threads == 1 {
        for i in lo..up {
            func(i)
        }
    } else {
        rayon::scope(|s| {
            for thread_idx in 0..n_threads {
                let func = &func;
                s.spawn(move |_| {
                    for i in (thread_idx..up).step_by(n_threads) {
                        func(i)
                    }
                });
            }
        })
    }
}