Method evaluate

datafusion/functions-aggregate/src/string_agg.rs:256–294

(&mut self)

    }

    fn evaluate(&mut self) -> Result<ScalarValue> {
        let scalar = self.array_agg_acc.evaluate()?;

        let ScalarValue::List(list) = scalar else {
            return internal_err!(
                "Expected a DataType::List while evaluating underlying ArrayAggAccumulator, but got {}",
                scalar.data_type()
            );
        };

        let string_arr: Vec<_> = match list.value_type() {
            DataType::LargeUtf8 => as_generic_string_array::<i64>(list.values())?
                .iter()
                .flatten()
                .collect(),
            DataType::Utf8 => as_generic_string_array::<i32>(list.values())?
                .iter()
                .flatten()
                .collect(),
            DataType::Utf8View => as_string_view_array(list.values())?
                .iter()
                .flatten()
                .collect(),
            _ => {
                return internal_err!(
                    "Expected elements to of type Utf8 or LargeUtf8, but got {}",
                    list.value_type()
                );
            }
        };

        if string_arr.is_empty() {
            return Ok(ScalarValue::LargeUtf8(None));
        }

        Ok(ScalarValue::LargeUtf8(Some(
            string_arr.join(&self.delimiter),
        )))
    }

    fn size(&self) -> usize {
        size_of_val(self) - size_of_val(&self.array_agg_acc)