Struct ReturnFieldArgs 

pub struct ReturnFieldArgs<'a> {
    pub arg_fields: &'a [FieldRef],
    pub scalar_arguments: &'a [Option<&'a ScalarValue>],
    pub lambdas: &'a [bool],
}

Information about arguments passed to the function

This structure contains metadata about how the function was called such as the type of the arguments, any scalar arguments and if the arguments can (ever) be null

See ScalarUDFImpl::return_field_from_args for more information

Fields

arg_fields: &'a [FieldRef]

The data types of the arguments to the function

If argument i to the function is a lambda, it will be the field returned by the lambda when executed with the arguments returned from ScalarUDFImpl::lambdas_parameters

For example, with array_transform([1], v -> v == 5) this field will be [Field::new("", DataType::List(DataType::Int32), false), Field::new("", DataType::Boolean, false)]

scalar_arguments: &'a [Option<&'a ScalarValue>]

Is argument i to the function a scalar (constant)?

If the argument i is not a scalar, it will be None

For example, if a function is called like my_function(column_a, 5) this field will be [None, Some(ScalarValue::Int32(Some(5)))]

lambdas: &'a [bool]

Is argument i to the function a lambda?

For example, with array_transform([1], v -> v == 5) this field will be [false, true]

Implementations

impl<'a> ReturnFieldArgs<'a>

pub fn to_lambda_args(&self) -> Vec<ValueOrLambdaField<'a>>

Based on self.lambdas, encodes self.arg_fields to tagged enums indicating whether it correspond to a value or a lambda argument

Trait Implementations

impl<'a> Debug for ReturnFieldArgs<'a>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.