Function get_scalar_value_from_args

datafusion/functions-window/src/utils.rs:36–52

(
    args: &[Arc<dyn PhysicalExpr>],
    index: usize,
)

}

pub(crate) fn get_scalar_value_from_args(
    args: &[Arc<dyn PhysicalExpr>],
    index: usize,
) -> Result<Option<ScalarValue>> {
    Ok(if let Some(field) = args.get(index) {
        let tmp = field
            .downcast_ref::<Literal>()
            .ok_or_else(|| DataFusionError::NotImplemented(
                format!("There is only support Literal types for field at idx: {index} in Window Function"),
            ))?
            .value()
            .clone();
        Some(tmp)
    } else {
        None
    })
}

pub(crate) fn get_unsigned_integer(value: &ScalarValue) -> Result<u64> {
    if value.is_null() {