Function create_example_udf

datafusion/sqllogictest/src/test_context.rs:516–546

Create a UDF function named "example". See the `sample_udf.rs` example file for an explanation of the API.

()

/// Create a UDF function named "example". See the `sample_udf.rs` example
/// file for an explanation of the API.
fn create_example_udf() -> ScalarUDF {
    let adder = Arc::new(|args: &[ColumnarValue]| {
        let ColumnarValue::Array(lhs) = &args[0] else {
            panic!("should be array")
        };
        let ColumnarValue::Array(rhs) = &args[1] else {
            panic!("should be array")
        };

        let lhs = as_float64_array(lhs).expect("cast failed");
        let rhs = as_float64_array(rhs).expect("cast failed");
        let array = lhs
            .iter()
            .zip(rhs.iter())
            .map(|(lhs, rhs)| match (lhs, rhs) {
                (Some(lhs), Some(rhs)) => Some(lhs + rhs),
                _ => None,
            })
            .collect::<Float64Array>();
        Ok(ColumnarValue::from(Arc::new(array) as ArrayRef))
    });
    create_udf(
        "example",
        // Expects two f64 values:
        vec![DataType::Float64, DataType::Float64],
        // Returns an f64 value:
        DataType::Float64,
        Volatility::Immutable,
        adder,
    )
}

fn register_union_table(ctx: &SessionContext) {
    let union = UnionArray::try_new(