Function elementwise

nodedb-array/src/query/elementwise.rs:33–61

Apply `op` to every aligned pair of cells. The result tile carries the union of both coord sets.

(
    schema: &ArraySchema,
    a: &SparseTile,
    b: &SparseTile,
    op: BinaryOp,
)

/// Apply `op` to every aligned pair of cells. The result tile carries
/// the union of both coord sets.
pub fn elementwise(
    schema: &ArraySchema,
    a: &SparseTile,
    b: &SparseTile,
    op: BinaryOp,
) -> ArrayResult<SparseTile> {
    let n_attrs = schema.attrs.len();
    let by_coord_a = index_rows(a);
    let by_coord_b = index_rows(b);
    let mut keys: BTreeMap<Vec<CoordKey>, ()> = BTreeMap::new();
    for k in by_coord_a.keys().chain(by_coord_b.keys()) {
        keys.insert(k.clone(), ());
    }

    let mut builder = SparseTileBuilder::new(schema);
    for key in keys.keys() {
        let coord = decode_key(key);
        let lhs = by_coord_a.get(key);
        let rhs = by_coord_b.get(key);
        let mut out = Vec::with_capacity(n_attrs);
        for i in 0..n_attrs {
            let l = lhs.map(|v| v[i].clone()).unwrap_or(CellValue::Null);
            let r = rhs.map(|v| v[i].clone()).unwrap_or(CellValue::Null);
            out.push(apply(&l, &r, op));
        }
        builder.push(&coord, &out)?;
    }
    Ok(builder.build())
}

fn apply(l: &CellValue, r: &CellValue, op: BinaryOp) -> CellValue {
    let (lf, rf) = match (to_f64(l), to_f64(r)) {