[ARROW-18295] [C++] FieldRef::FindAll/FindOne(DataType) improve error

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Fix Version/s: 11.0.0
• Component/s: C++
• External issue URL: https://github.com/apache/arrow/issues/20492
• Assignee: Miles Granger
• Reporter: Miles Granger
• Created: 09/Nov/22 11:33
• Updated: 11/Jan/23 11:59

Description

GitHub PR 14495 adds support for struct_field to accept string field names (as well as a mix of indices/strings). A side effect is the error produced by FieldRef::FindOne and by proxy FieldRef::FindAll does not give as good of an error as the previous StructFieldFunctor::CheckIndex did.

See the GitHub discussion here for more context

It would be good to have a similar error message given when using FieldRef::FineOne on a DataType.

Example error from StructFieldFunctor::CheckIndex:
out-of-bounds field reference to field 4 in type struct<a: int32, b: string, c: struct<d: int64, e: double>> with 3 fields

Error from FieldRef::FindOne:
No match for FieldRef.FieldPath(2 4) in struct<a: int32, b: string, c: struct<d: int64, e: double>>

Issue Links

• relates to: ARROW-17989 [C++] Enable struct_field kernel to accept string field names