[ARROW-8779] [R] Implement conversion to List<Struct>

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.16.0, 0.17.0
• Fix Version/s: 1.0.0
• Component/s: R
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/17178
• Assignee: Romain Francois
• Reporter: Dominic Dennenmoser
• Created: 12/May/20 20:39
• Updated: 11/Jan/23 08:02
• Resolved: 16/Jun/20 22:11

Description

It seems there is no method implemented to write a StructArrow (within a TableArrow) to file. A common case would be list columns in a dataframe. If I have understood the documentation correctly, the should be realisable within the current C++ library framework.

I tested this with the follow df structure:

df
|-- id <column: string>
|-- data <column: list>
|   |-- a <column: string>
|   |-- b <column: integer>
|   |-- c <column: factor>
|   |-- d <column: double>

 I got the follow error message:

Error in Table__from_dots(dots, schema) : NotImplemented: Converting vector to arrow type struct<a: string, b: int32, c: dictionary<values=string, indices=int8, ordered=0>, d: double> not implemented

 I have tried it with arrow 0.17.0 under R 3.6.1 .

Issue Links

• links to: GitHub Pull Request #7435