[ARROW-14999] [C++] List types with different field names are not equal

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 6.0.0
• Fix Version/s: 11.0.0
• Component/s: C++
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/30519
• Assignee: Will Jones
• Reporter: Will Jones
• Created: 06/Dec/21 20:57
• Updated: 11/Jan/23 08:43
• Resolved: 08/Dec/22 16:01

Description

When comparing map types, the names of the fields are ignored. This was introduced in ARROW-7173.

However for list types, they are not ignored. For example,

In [6]: l1 = pa.list_(pa.field("val", pa.int64()))

In [7]: l2 = pa.list_(pa.int64())

In [8]: l1
Out[8]: ListType(list<val: int64>)

In [9]: l2
Out[9]: ListType(list<item: int64>)

In [10]: l1 == l2
Out[10]: False

Should we make list type comparison ignore field names too?

Issue Links

• relates to: ARROW-18411 [Python] MapType comparison ignores nullable flag of item_field
• links to: GitHub Pull Request #13851
• links to: GitHub Pull Request #14847