Function arrow_arith::arity::binary

source · 
pub fn binary<A, B, F, O>(
    a: &PrimitiveArray<A>,
    b: &PrimitiveArray<B>,
    op: F,
) -> Result<PrimitiveArray<O>, ArrowError>
where
    A: ArrowPrimitiveType,
    B: ArrowPrimitiveType,
    O: ArrowPrimitiveType,
    F: Fn(A::Native, B::Native) -> O::Native,
Expand description

Allies a binary infallable function to two PrimitiveArrays, producing a new PrimitiveArray

§Details

Given two arrays of length len, calls op(a[i], b[i]) for i in 0..len, collecting the results in a PrimitiveArray.

If any index is null in either a or b, the corresponding index in the result will also be null

Like unary, the op is evaluated for every element in the two arrays, including those elements which are NULL. This is beneficial as the cost of the operation is low compared to the cost of branching, and especially when the operation can be vectorised, however, requires op to be infallible for all possible values of its inputs

§Errors

  • if the arrays have different lengths.

§Example

let a = Float32Array::from(vec![Some(5.1f32), None, Some(6.8), Some(7.2)]);
let b = Int32Array::from(vec![1, 2, 4, 9]);
// compute int(a) + b for each element
let c = binary(&a, &b, |a, b| a as i32 + b).unwrap();
assert_eq!(c, Int32Array::from(vec![Some(6), None, Some(10), Some(16)]));