Function intersection

rust/stringzilla.rs:2274–2304

Intersects two sequences (inner join) using their default byte-slice views. Both sequences must have an output buffer provided (for first and second positions) whose length is at least the minimum of the two input lengths. # Example ```rust use stringzilla::stringzilla as sz; let set1 = ["banana", "apple", "cherry"]; let set2 = ["cherry", "orange", "pineapple", "banana"]; let mut positions1 =

(
    data1: &[T],
    data2: &[T],
    seed: u64,
    positions1: &mut [SortedIdx],
    positions2: &mut [SortedIdx],
)

/// assert!(n == 2); // "banana" and "cherry" are common.
/// ```
pub fn intersection<T: AsRef<[u8]>>(
    data1: &[T],
    data2: &[T],
    seed: u64,
    positions1: &mut [SortedIdx],
    positions2: &mut [SortedIdx],
) -> Result<usize, Status> {
    let min_count = data1.len().min(data2.len());
    if positions1.len() < min_count || positions2.len() < min_count {
        return Err(Status::BadAlloc);
    }

    // Call the lower-level implementation with accurate counts for both sequences.
    let adapter1 = move |i: usize| -> &'static [u8] {
        // SAFETY: used only during the FFI call
        unsafe { core::mem::transmute::<&[u8], &'static [u8]>(data1[i].as_ref()) }
    };
    let adapter2 = move |j: usize| -> &'static [u8] {
        // SAFETY: used only during the FFI call
        unsafe { core::mem::transmute::<&[u8], &'static [u8]>(data2[j].as_ref()) }
    };
    _intersection_by_impl(
        adapter1,
        adapter2,
        seed,
        positions1,
        positions2,
        data1.len(),
        data2.len(),
    )
}

/// Intersects two sequences (inner join) using their elements corresponding byte-slice views.
/// The caller must provide a closure that maps an index to the byte slice representation of