Function datafusion::logical_plan::create_udf

pub fn create_udf(
    name: &str, 
    input_types: Vec<DataType>, 
    return_type: Arc<DataType>, 
    volatility: Volatility, 
    fun: ScalarFunctionImplementation
) -> ScalarUDF

Creates a new UDF with a specific signature and specific return type. This is a helper function to create a new UDF. The function create_udf returns a subset of all possible ScalarFunction:

• the UDF has a fixed return type
• the UDF has a fixed signature (e.g. [f64, f64])