Function parse_default_value

datafusion/functions-window/src/lead_lag.rs:391–402

Handles type coercion and null value refinement for default value argument depending on the data type of the input expression.

(
    input_exprs: &[Arc<dyn PhysicalExpr>],
    input_types: &[FieldRef],
)

/// Handles type coercion and null value refinement for default value
/// argument depending on the data type of the input expression.
fn parse_default_value(
    input_exprs: &[Arc<dyn PhysicalExpr>],
    input_types: &[FieldRef],
) -> Result<ScalarValue> {
    let expr_field = parse_expr_field(input_types)?;
    let unparsed = get_scalar_value_from_args(input_exprs, 2)?;

    unparsed
        .filter(|v| !v.data_type().is_null())
        .map(|v| v.cast_to(expr_field.data_type()))
        .unwrap_or_else(|| ScalarValue::try_from(expr_field.data_type()))
}

#[derive(Debug)]
struct WindowShiftEvaluator {